Local reactions included redness, swelling, and pain at the injection site occurring at the BNT162b2 or placebo injection site. Local reactions were recorded by participants in an electronic diary (e-diary). Redness and swelling were measured and recorded in measuring device units. 1 measuring device unit =0.5 centimeter (cm) and graded as mild: greater than (\>) 2.0 to 5.0 cm, moderate: \>5.0 to 10.0 cm, severe: \>10.0 cm, and potentially life threatening (Grade 4): necrosis or exfoliative dermatitis. Pain at injection site was graded as mild: did not interfere with daily activity, moderate: interfered with daily activity, severe: prevented daily activity, and potentially life threatening (Grade 4): emergency room visit or hospitalization for severe pain. Exact 2-sided confidence interval (CI), based on the Clopper and Pearson method was used.

Local reactions included redness, swelling, and pain at the injection site occurring at the BNT162b2 or placebo injection site. Local reactions were recorded by participants in an e-diary. Redness and swelling were measured and recorded in measuring device units. 1 measuring device unit =0.5 cm and graded as mild: greater than \>2.0 to 5.0 cm, moderate: \>5.0 to 10.0 cm, severe: \>10.0 cm, and potentially life threatening (Grade 4): necrosis or exfoliative dermatitis. Pain at injection site was graded as mild: did not interfere with daily activity, moderate: interfered with daily activity, severe: prevented daily activity, and potentially life threatening (Grade 4): emergency room visit or hospitalization for severe pain. Exact 2-sided CI, based on the Clopper and Pearson method was used.

Systemic events included fever, fatigue, headache, chills, vomiting, diarrhea, new or worsened muscle pain, and new or worsened joint pain recorded by participants in an e-diary. Fever was defined as temperature: \>=38.0 degrees (deg) Celsius (C), and categorized as: \>=38.0 to 38.4 deg C, \>38.4 to 38.9 deg C, \>38.9 to 40.0 deg C, and \>40.0 deg C. Fatigue, headache, chills, new or worsened muscle pain, and new or worsened joint pain were graded as mild: did not interfere with activity, moderate: some interference with activity, and severe: prevented daily routine activity. Vomiting graded as mild: 1 to 2 times in 24 hours(h), moderate: \>2 times in 24h, severe: required intravenous hydration, and grade 4: emergency room (ER) visit or hospitalization for hypotensive shock. Diarrhea graded as mild: 2 to 3 loose stools in 24h, moderate: 4 to 5 loose stools in 24h, severe: 6 or more loose stools in 24h, and grade 4: ER visit or hospitalization for severe diarrhea.

Systemic events included fever, fatigue, headache, chills, vomiting, diarrhea, new or worsened muscle pain, and new or worsened joint pain recorded by participants in an e-diary. Fever was defined as temperature: \>=38.0 deg C, and categorized as: \>=38.0 to 38.4 deg C, \>38.4 to 38.9 deg C, \>38.9 to 40.0 deg C, and \>40.0 deg C. Fatigue, headache, chills, new or worsened muscle pain, and new or worsened joint pain were graded as mild: did not interfere with activity, moderate: some interference with activity, and severe: prevented daily routine activity. Vomiting graded as mild: 1 to 2 times in 24h, moderate: \>2 times in 24h, severe: required intravenous hydration, and grade 4: ER visit or hospitalization for hypotensive shock. Diarrhea graded as mild: 2 to 3 loose stools in 24h, moderate: 4 to 5 loose stools in 24h, severe: 6 or more loose stools in 24h, and grade 4: ER visit or hospitalization for severe diarrhea. Exact 2-sided CI, based on Clopper and Pearson method used.

An AE was defined as any untoward medical occurrence in a clinical study participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention. Exact 2-sided CI was calculated using the Clopper and Pearson method. Only AEs collected by non-systematic assessment (i.e. excluding local reactions and systemic events) were reported in this outcome measure.

An AE was defined as any untoward medical occurrence in a clinical study participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention. Exact 2-sided CI was calculated using the Clopper and Pearson method. Only AEs collected by non-systematic assessment (i.e. excluding local reactions and systemic events) were reported in this outcome measure.

An AE was defined as any untoward medical occurrence in a clinical study participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention. Exact 2-sided CI was calculated using the Clopper and Pearson method. SAE was an AE resulting in any of the following outcomes or deemed significant for any other reason: death; initial/prolonged inpatient hospitalization; life-threatening experience (immediate risk of dying); persistent or significant disability/incapacity; congenital anomaly; or that was considered to be an important medical event.

An AE was defined as any untoward medical occurrence in a clinical study participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention. Exact 2-sided CI was calculated using the Clopper and Pearson method. SAE was an AE resulting in any of the following outcomes or deemed significant for any other reason: death; initial/prolonged inpatient hospitalization; life-threatening experience (immediate risk of dying); persistent or significant disability/incapacity; congenital anomaly; or that was considered to be an important medical event.

GMCs of full-length S-binding IgG level for the coadministration group and separate administration group were reported in this outcome measure in descriptive data section. GMC and the 2-sided 95% CI were calculated by exponentiating the LSMeans of the concentrations and the corresponding CIs based on analysis of logarithmically transformed assay results using a linear regression model with terms of vaccine group, age group, and the corresponding baseline assay results (log scale). Assay results below the LLOQ were set to 0.5\*LLOQ. Geometric mean ratio (GMR) was reported in the statistical analysis section and was calculated as ratio of GMCs in the coadministration group to the separate administration group. Here, "Number of participants analyzed" signifies number of participants evaluable for this outcome measure.

GMTs of strain-specific HAI titers for the coadministration group and separate administration group were reported in this outcome measure in descriptive data section. GMTs and the 2-sided 95% CIs were calculated by exponentiating the LSMeans of the titers and the corresponding CIs based on analysis of logarithmically transformed assay results using a linear regression model with terms of vaccine group, age group, and the corresponding baseline assay results (log scale). Assay results below the LLOQ were set to 0.5\*LLOQ, and results above the ULOQ were set to ULOQ+1. Geometric mean ratio (GMR) was reported in the statistical analysis section and was calculated as ratio of GMT in the coadministration group to the separate administration group.

Occurrences (number of cases) of first COVID-19 infection in participants after booster dose per 1000 person-year, without past SARS-CoV-2 infection at interim analysis were reported in this outcome measure.

Occurrences (number of cases) of first COVID-19 infection in participants after booster dose with and without past SARS-CoV-2 infection at interim analysis were reported in this outcome measure.

Occurrences (number of cases) of first COVID-19 infection in participants after booster dose without past SARS-CoV-2 infection at final analysis were reported in this outcome measure.

Occurrences (number of cases) of first COVID-19 infection in participants after booster dose with and without past SARS-CoV-2 infection at final analysis were reported in this outcome measure.

An AE was any untoward medical occurrence in a participant temporally associated with the use of study intervention, whether or not considered related to the study intervention.

An SAE was defined as any untoward medical occurrence at any dose that resulted in any of the following outcomes: death; life-threatening (immediate risk of death); required inpatient hospitalization or prolongation of existing hospitalization; persistent or significant disability/incapacity (substantial disruption of the ability to conduct normal life functions); congenital anomaly/birth defect; or that was considered as an important medical event.

Percentage of participants with elevated troponin I levels before administration of Vaccination 1 were reported in this outcome measure.

Percentage of participants with elevated troponin I levels within 5 days after administration of Vaccination 1 were reported in this outcome measure.

Percentage of participants with elevated troponin I levels pre vaccination 2 were reported in this outcome measure.

Percentage of participants with elevated troponin I levels within 5 days after administration of Vaccination 2 were reported in this outcome measure.

Percentage of participants with elevated troponin I levels within 1 month after administration of Vaccination 2 were reported in this outcome measure.

Local reactions were recorded by participants in e-diary. Redness and swelling were measured and recorded in measuring device units (mdu) where, 1 mdu =0.5 centimeter (cm) and were graded as mild (greater than \[\>\] 2.0 to 5.0 cm), moderate (\>5.0 to 10.0 cm), severe (\>10.0 cm) and Grade 4 (necrosis \[swelling\] or necrosis or exfoliative dermatitis \[redness\]). Pain at injection site was graded as mild (did not interfere with activity), moderate (interfered with activity), severe (prevented daily activity) and Grade 4 (emergency room \[ER\] visit or hospitalization for severe pain at injection site). Grade 4 were classified by investigator or medically qualified person. Percentage of participants reporting local reactions after Vaccination 1 and associated 2-sided 95% confidence interval (CI) based on Clopper and Pearson method was presented.

Local reactions were recorded by participants in e-diary. Redness and swelling were measured and recorded in measuring device units (mdu) where, 1 mdu =0.5 centimeter (cm) and were graded as mild (greater than \[\>\] 2.0 to 5.0 cm), moderate (\>5.0 to 10.0 cm), severe (\>10.0 cm) and Grade 4 (necrosis \[swelling\] or necrosis or exfoliative dermatitis \[redness\]). Pain at injection site was graded as mild (did not interfere with activity), moderate (interfered with activity), severe (prevented daily activity) and Grade 4 (emergency room \[ER\] visit or hospitalization for severe pain at injection site). Grade 4 were classified by investigator or medically qualified person. Percentage of participants reporting local reactions after Vaccination 2 and associated 2-sided 95% confidence interval (CI) based on Clopper and Pearson method was presented.

Systemic events were recorded in e-diary. Fever: oral temperature greater than or equal to (\>=) 38.0 degree Celsius (deg C) and categorized as \>=38.0-38.4 deg C, \>38.4-38.9 deg C, \>38.9-40.0 deg C and \>40.0 deg C. Fatigue, headache, chills, new or worsened muscle pain and new or worsened joint pain: mild (did not interfere with activity), moderate (some interference with activity), severe (prevented daily routine activity) and Grade 4 (ER visit/hospitalization). Vomiting: mild: 1-2 times in 24 hours (h), moderate: \>2 times in 24h, severe: required intravenous hydration and Grade 4: ER visit/hospitalization for hypotensive shock. Diarrhea: mild: 2-3 loose stools in 24h, moderate: 4-5 loose stools in 24h, severe: 6 or more loose stools in 24h and Grade 4: ER visit/hospitalization for severe diarrhea. Grade 4 were classified by investigator or medically qualified person. Exact 95% CI was based on Clopper and Pearson method.

Systemic events were recorded in e-diary. Fever: oral temperature greater than or equal to (\>=) 38.0 degree Celsius (deg C) and categorized as \>=38.0-38.4 deg C, \>38.4-38.9 deg C, \>38.9-40.0 deg C and \>40.0 deg C. Fatigue, headache, chills, new or worsened muscle pain and new or worsened joint pain: mild (did not interfere with activity), moderate (some interference with activity), severe (prevented daily routine activity) and Grade 4 (ER visit/hospitalization). Vomiting: mild: 1-2 times in 24 hours (h), moderate: \>2 times in 24h, severe: required intravenous hydration and Grade 4: ER visit/hospitalization for hypotensive shock. Diarrhea: mild: 2-3 loose stools in 24h, moderate: 4-5 loose stools in 24h, severe: 6 or more loose stools in 24h and Grade 4: ER visit/hospitalization for severe diarrhea. Grade 4 were classified by investigator or medically qualified person. Exact 95% CI was based on Clopper and Pearson method.

An AE was defined as any untoward medical occurrence in a clinical study participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention. Percentage of participants reporting AEs within 1 month after Vaccination 1 were reported in this outcome measure. Exact 2-sided CI was calculated using the Clopper and Pearson method. Only AEs collected by non-systematic assessment (i.e., excluding local reactions and systemic events) were reported in this outcome measure.

An AE was defined as any untoward medical occurrence in a clinical study participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention. Percentage of participants reporting AEs within 1 month after Vaccination 2 were reported in this outcome measure. Exact 2-sided CI was calculated using the Clopper and Pearson method. Only AEs collected by non-systematic assessment (i.e., excluding local reactions and systemic events) were reported in this outcome measure.

An SAE was defined as any untoward medical occurrence that at any dose resulted in death, was life-threatening; resulted in persistent disability/incapacity; constituted a congenital anomaly/birth defect; was important medical event; required inpatient hospitalization or prolongation of existing hospitalization. Exact 2-sided 95% CI was based on the Clopper and Pearson method.

An SAE was defined as any untoward medical occurrence that at any dose resulted in death, was life-threatening; resulted in persistent disability/incapacity; constituted a congenital anomaly/birth defect; was important medical event; required inpatient hospitalization or prolongation of existing hospitalization. Exact 2-sided 95% CI was based on the Clopper and Pearson method.

Local reactions were recorded by participants in e-diary. Redness and swelling were measured and recorded in measuring device units (mdu) where, 1 mdu =0.5 cm and were graded as mild (greater than \[\>\] 2.0 to 5.0 cm), moderate (\>5.0 to 10.0 cm), severe (\>10.0 cm) and Grade 4 (necrosis \[swelling\] or necrosis or exfoliative dermatitis \[redness\]). Pain at injection site was graded as mild (did not interfere with activity), moderate (interfered with activity), severe (prevented daily activity) and Grade 4 (emergency room \[ER\] visit or hospitalization for severe pain at injection site). Grade 4 were classified by investigator or medically qualified person. Percentage of participants reporting local reactions after the booster (third) dose and associated 2-sided 95% confidence interval (CI) based on Clopper and Pearson method was presented.

Systemic events were recorded in e-diary. Fever: oral temperature greater than or equal to (\>=) 38.0 degree Celsius (deg C) and categorized as \>=38.0-38.4 deg C, \>38.4-38.9 deg C, \>38.9-40.0 deg C and \>40.0 deg C. Fatigue, headache, chills, new or worsened muscle pain and new or worsened joint pain: mild (did not interfere with activity), moderate (some interference with activity), severe (prevented daily routine activity) and Grade 4 (ER visit/hospitalization). Vomiting: mild: 1-2 times in 24 hours (h), moderate: \>2 times in 24h, severe: required intravenous hydration and Grade 4: ER visit/hospitalization for hypotensive shock. Diarrhea: mild: 2-3 loose stools in 24 h, moderate: 4-5 loose stools in 24h, severe: 6 or more loose stools in 24h and Grade 4: ER visit/hospitalization for severe diarrhea. Grade 4 were classified by investigator or medically qualified person. Exact 95% CI was based on Clopper and Pearson method.

An AE was defined as any untoward medical occurrence in a clinical study participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention. Percentage of participants reporting AEs from booster (third) dose up to 1 month after booster (third) dose were reported in this outcome measure. Exact 2-sided CI was calculated using the Clopper and Pearson method. Only AEs collected by non-systematic assessment (i.e., excluding local reactions and systemic events) were reported in this outcome measure.

An SAE was defined as any untoward medical occurrence that at any dose resulted in death, was life-threatening; resulted in persistent disability/incapacity; constituted a congenital anomaly/birth defect; was important medical event; required inpatient hospitalization or prolongation of existing hospitalization. Exact 2-sided 95% CI was based on the Clopper and Pearson method.

GMT of SARS-CoV-2 reference-strain-neutralizing titers at baseline (before the booster dose) was reported in this outcome measure. GMTs and the corresponding 2-sided CIs were calculated by exponentiating the mean logarithm of the titers and the corresponding CIs (based on Student's t distribution).

GMT of SARS-CoV-2 reference-strain-neutralizing titers at 1 month after the booster dose was reported in this outcome measure. GMTs and the corresponding 2-sided CIs were calculated by exponentiating the mean logarithm of the titers and the corresponding CIs (based on Student's t distribution).

GMFR of SARS-CoV-2 reference-strain-neutralizing titers from baseline to 1 month after the booster dose received in this sub-study was reported in this outcome measure. GMFR and the corresponding 2-sided CIs were calculated by exponentiating the mean logarithm of the fold rises from before vaccination and the corresponding CIs (based on the student's t distribution).

Seroresponse was defined as achieving \>= 4-fold rise from baseline (before the study vaccination). If the baseline measurement is below the lower limit of quantification (LLOQ), the postvaccination measure of \>= 4 × LLOQ is considered a seroresponse. Exact 2-sided CI, based on the Clopper and Pearson method was used. Percentage of participants achieving seroresponse at 1 month after the booster dose was reported in this outcome measure.

Local reactions were recorded by participants in e-diary. Redness and swelling were measured and recorded in measuring device units (mdu) where, 1 mdu=0.5 centimeter (cm) and were graded as mild (\> 2.0 to 5.0 cm), moderate (\>5.0 to 10.0 cm), severe (\>10.0 cm) and Grade 4 (necrosis \[swelling\] or necrosis or exfoliative dermatitis \[redness\]). Pain at injection (inj) site was graded as mild (did not interfere with activity), moderate (interfered with activity), severe (prevented daily activity) and Grade 4 (emergency room \[ER\] visit/hospitalization for severe pain at injection site). Grade 4 were classified by investigator or medically qualified person. Percentage of participants reporting local reactions after Vaccination 1 and associated 2-sided 95% confidence interval (CI) based on Clopper and Pearson method was presented.

Local reactions were recorded by participants in e-diary. Redness and swelling were measured and recorded in measuring device units (mdu) where, 1 mdu =0.5 centimeter (cm) and were graded as mild (\> 2.0 to 5.0 cm), moderate (\>5.0 to 10.0 cm), severe (\>10.0 cm) and Grade 4 (necrosis \[swelling\] or necrosis or exfoliative dermatitis \[redness\]). Pain at injection site was graded as mild (did not interfere with activity), moderate (interfered with activity), severe (prevented daily activity) and Grade 4 (emergency room \[ER\] visit or hospitalization for severe pain at injection site). Grade 4 were classified by investigator or medically qualified person. Percentage of participants reporting local reactions after Vaccination 2 and associated 2-sided 95% confidence interval (CI) based on Clopper and Pearson method was presented.

Local reactions were recorded by participants in e-diary. Redness and swelling were measured and recorded in measuring device units (mdu) where, 1 mdu =0.5 centimeter (cm) and were graded as mild (\> 2.0 to 5.0 cm), moderate (\>5.0 to 10.0 cm), severe (\>10.0 cm) and Grade 4 (necrosis \[swelling\] or necrosis or exfoliative dermatitis \[redness\]). Pain at injection site was graded as mild (did not interfere with activity), moderate (interfered with activity), severe (prevented daily activity) and Grade 4 (emergency room \[ER\] visit or hospitalization for severe pain at injection site). Grade 4 were classified by investigator or medically qualified person. Percentage of participants reporting local reactions after Vaccination 3 and associated 2-sided 95% confidence interval (CI) based on Clopper and Pearson method was presented.

Systemic events were recorded in e-diary. Fever: oral temperature \>= 38.0 deg C, categorized as \>=38.0-38.4 deg C, \>38.4-38.9 deg C, \>38.9-40.0 deg C and \>40.0 deg C. Fatigue, headache, chills, new or worsened muscle pain and new or worsened joint pain: mild (did not interfere with activity), moderate (some interference with activity), severe (prevented daily routine activity) and Grade 4 (ER visit/hospitalization). Vomiting: mild: 1-2 times in 24 h, moderate: \>2 times in 24h, severe: required intravenous hydration and Grade 4: ER visit/hospitalization for hypotensive shock. Diarrhea: mild: 2-3 loose stools in 24h, moderate: 4-5 loose stools in 24h, severe: 6 or more loose stools in 24h and Grade 4: ER visit/hospitalization for severe diarrhea. Grade 4 were classified by investigator or medically qualified person. Exact 95% CI was based on Clopper and Pearson method.

Systemic events were recorded in e-diary. Fever: oral temperature \>= 38.0 deg C, categorized as \>=38.0-38.4 deg C, \>38.4-38.9 deg C, \>38.9-40.0 deg C and \>40.0 deg C. Fatigue, headache, chills, new or worsened muscle pain and new or worsened joint pain: mild (did not interfere with activity), moderate (some interference with activity), severe (prevented daily routine activity) and Grade 4 (ER visit/hospitalization). Vomiting: mild: 1-2 times in 24 h, moderate: \>2 times in 24h, severe: required intravenous hydration and Grade 4: ER visit/hospitalization for hypotensive shock. Diarrhea: mild: 2-3 loose stools in 24h, moderate: 4-5 loose stools in 24h, severe: 6 or more loose stools in 24h and Grade 4: ER visit/hospitalization for severe diarrhea. Grade 4 were classified by investigator or medically qualified person. Exact 95% CI was based on Clopper and Pearson method.

Systemic events were recorded in e-diary. Fever: oral temperature \>= 38.0 deg C and categorized as \>=38.0-38.4 deg C, \>38.4-38.9 deg C, \>38.9-40.0 deg C and \>40.0 deg C. Fatigue, headache, chills, new or worsened muscle pain and new or worsened joint pain: mild (did not interfere with activity), moderate (some interference with activity), severe (prevented daily routine activity) and Grade 4 (ER visit/hospitalization). Vomiting: mild: 1-2 times in 24 hours (h), moderate: \>2 times in 24h, severe: required intravenous hydration and Grade 4: ER visit/hospitalization for hypotensive shock. Diarrhea: mild: 2-3 loose stools in 24h, moderate: 4-5 loose stools in 24h, severe: 6 or more loose stools in 24h and Grade 4: ER visit/hospitalization for severe diarrhea. Grade 4 were classified by investigator or medically qualified person. Exact 95% CI was based on Clopper and Pearson method.

An AE was defined as any untoward medical occurrence in a clinical study participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention. Percentage of participants reporting AEs from first study vaccination (Day 1) up to 1 month after last study vaccination were reported in this outcome measure. Exact 2-sided CI was calculated using the Clopper and Pearson method. Only AEs collected by non-systematic assessment (i.e., excluding local reactions and systemic events) were reported in this outcome measure.

An AE was defined as any untoward medical occurrence in a clinical study participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention. Percentage of participants reporting AEs from first study vaccination (Day 1) up to 1 month after Vaccination 1 were reported in this outcome measure. Exact 2-sided CI was calculated using the Clopper and Pearson method. Only AEs collected by non-systematic assessment (i.e., excluding local reactions and systemic events) were reported in this outcome measure.

An AE was defined as any untoward medical occurrence in a clinical study participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention. Percentage of participants reporting AEs from Vaccination 2 up to 1 month after Vaccination 2 were reported in this outcome measure. Exact 2-sided CI was calculated using the Clopper and Pearson method. Only AEs collected by non-systematic assessment (i.e., excluding local reactions and systemic events) were reported in this outcome measure.

An AE was defined as any untoward medical occurrence in a clinical study participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention. Percentage of participants reporting AEs from first study vaccination (Day 1) up to 1 month after Vaccination 2 were reported in this outcome measure. Exact 2-sided CI was calculated using the Clopper and Pearson method. Only AEs collected by non-systematic assessment (i.e., excluding local reactions and systemic events) were reported in this outcome measure.

An AE was defined as any untoward medical occurrence in a clinical study participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention. Percentage of participants reporting AEs from Vaccination 3 up to 1 month after Vaccination 3 were reported in this outcome measure. Exact 2-sided CI was calculated using the Clopper and Pearson method. Only AEs collected by non-systematic assessment (i.e., excluding local reactions and systemic events) were reported in this outcome measure.

A SAE was defined as any untoward medical occurrence that at any dose resulted in death, was life-threatening; resulted in persistent disability/incapacity; constituted a congenital anomaly/birth defect; was important medical event; required inpatient hospitalization or prolongation of existing hospitalization. Exact 2-sided 95% CI was based on the Clopper and Pearson method.

A SAE was defined as any untoward medical occurrence that at any dose resulted in death, was life-threatening; resulted in persistent disability/incapacity; constituted a congenital anomaly/birth defect; was important medical event; required inpatient hospitalization or prolongation of existing hospitalization. Exact 2-sided 95% CI was based on the Clopper and Pearson method.

A SAE was defined as any untoward medical occurrence that at any dose resulted in death, was life-threatening; resulted in persistent disability/incapacity; constituted a congenital anomaly/birth defect; was important medical event; required inpatient hospitalization or prolongation of existing hospitalization. Exact 2-sided 95% CI was based on the Clopper and Pearson method.

GMR was calculated based on GMT levels of SSD: Cohort 2: Group 3 and SSD: Cohort 2: Group 4 and reported in statistical analysis section below. GMT of SARS-CoV-2 Omicron strain-neutralizing titers and reported in statistical analysis. GMT of SARS-CoV-2 Omicron BA.1 strain-neutralizing titers at 1 month after first study vaccination was reported in this outcome measure. GMTs and the corresponding 2-sided CIs were calculated by exponentiating the mean logarithm of the titers and the corresponding CIs (based on Student's t distribution).

Seroresponse: achieving \>= 4-fold rise from baseline (before study vaccination). If baseline measurement is below the lower limit of quantification (LLOQ), the postvaccination measure of \>= 4 × LLOQ is considered a seroresponse. Exact 2-sided CI, based on the Clopper and Pearson method was used. Percentage of participants achieving seroresponse 1 month after first study vaccination was reported in this outcome measure.

GMR was calculated based on the GMT of SARS-CoV-2 Omicron BA.1 strain-neutralizing titers and reported in statistical analysis. GMT of SARS-CoV-2 Omicron BA.1 strain-neutralizing titers at 1 month after first study vaccination was reported in this outcome measure. GMTs and the corresponding 2-sided CIs were calculated by exponentiating the mean logarithm of the titers and the corresponding CIs (based on Student's t distribution).

GMR was calculated based on GMT of SARS-CoV-2 Omicron BA.1 strain-neutralizing titers and reported in statistical analysis. GMT of SARS-CoV-2 Omicron BA.1 strain-neutralizing titers at 1 month after Vaccination 2 for Group 2 and 1 month after Vaccination 1 for Group 2b was reported. GMTs and corresponding 2-sided CIs were calculated by exponentiating mean logarithm of titers and corresponding CIs (based on Student's t distribution).

Seroresponse: achieving \>= 4-fold rise from baseline (before study vaccination). If baseline measurement is below lower limit of quantification (LLOQ), the postvaccination measure of \>= 4 × LLOQ is considered a seroresponse. Exact 2-sided CI, based on the Clopper and Pearson method was used. Percentage of participants achieving seroresponse 1 month after first study vaccination was reported in this outcome measure.

Seroresponse: achieving \>= 4-fold rise from baseline (before study vaccination). If baseline measurement is below LLOQ, postvaccination measure of \>= 4 × LLOQ is considered seroresponse. Exact 2-sided CI, based on Clopper and Pearson method was used. Percentage of participants achieving seroresponse 1 month after second study vaccination for Group 2 and 1 month after study vaccination for Group 2b was reported in this outcome measure.

GMR calculated based on GMT of SARS-CoV-2 Omicron BA.1 strain-neutralizing titers and reported in statistical analysis. GMR comparison between GMT of SARS-CoV-2 Omicron BA.1 strain-neutralizing titers of participants of SSD Cohort 3: Group 5 to GMT of SARS-CoV-2 Omicron BA.1 strain-neutralizing titers of participants of study C4591001 (NCT04368728) Phase 3 BNT162b2 single arm 18-55 years of age, at 1 month after vaccination 2 was reported. GMTs and corresponding 2-sided CIs were calculated by exponentiating mean logarithm of titers and corresponding CIs (student's t distribution).

EIP:eligible participants received 2 doses of study drug as randomized with Dose2 received within 19-42 days after Dose1 (SSD Cohort 3:Group 5), had valid determinate immunogenicity result from blood sample collected within 28-42 days after 2nd study vaccination, had no other important protocol deviations as determined by clinician. Data of eligible participants from Study C4591001 Phase 3 BNT162b2 single arm 18-55 years was included for comparison.'N'=participants evaluable for outcome measure.

Local reactions were recorded by participants in e-diary. Redness and swelling were measured and recorded in measuring device units (mdu) where, 1 mdu=0.5 centimeter (cm) and were graded as mild (greater than \[\>\] 2.0 to 5.0 cm), moderate (\>5.0 to 10.0 cm),severe (\>10.0 cm) and Grade 4 (necrosis \[swelling\] or necrosis/exfoliative dermatitis \[redness\]).Pain at injection site was graded as mild (did not interfere with activity),moderate (interfered with activity), severe (prevented daily activity) and Grade 4 (emergency room \[ER\] visit/hospitalization for severe pain). Grade 4 were classified by investigator or medically qualified person. Percentage of participants reporting local reactions within 7 days after study vaccination and associated 2-sided 95% confidence interval (CI) based on Clopper and Pearson method was presented.

Systemic events were recorded in e-diary. Fever: oral temperature greater than or equal to 38.0 deg C and categorized as \>=38.0-38.4 deg C, \>38.4-38.9 deg C, \>38.9-40.0 deg C \& \>40.0 deg C. Fatigue, headache, chills, muscle pain and joint pain: mild (did not interfere with activity), moderate (some interference with activity), severe (prevented daily routine activity) and Grade 4 (ER visit or hospitalization). Vomiting: mild: 1-2 times in 24 h, moderate: \> 2 times in 24h, severe: required intravenous hydration and Grade 4: ER or hospitalization for hypotensive shock. Diarrhea: mild: 2-3 loose stools in 24h, moderate: 4-5 loose stools in 24h, severe: 6 or more loose stools in 24h and Grade 4: ER visit or hospitalization for severe diarrhea. Grade 4 were classified by investigator or medically qualified person. Exact 95% CI was based on Clopper and Pearson method.

An AE was defined as any untoward medical occurrence in a clinical study participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention. Percentage of participants reporting AEs within 1 month after study vaccination were reported in this outcome measure. Exact 2-sided CI was calculated using the Clopper and Pearson method. Only AEs collected by non-systematic assessment (i.e., excluding local reactions and systemic events) were reported in this outcome measure.

An SAE was defined as any untoward medical occurrence that at any dose resulted in death, was life-threatening; resulted in persistent disability/incapacity; constituted a congenital anomaly/birth defect; was important medical event; required inpatient hospitalization or prolongation of existing hospitalization. Exact 2-sided 95% CI was based on the Clopper and Pearson method.

Percentage of participants with elevated troponin I levels before study vaccination were reported in this outcome measure.

Percentage of participants with elevated troponin I levels before study vaccination were reported in this outcome measure.

GMR calculated based on GMT of SARS-CoV-2 Omicron BA.1 strain-neutralizing titers and reported in statistical analysis. GMT of SARS-CoV-2 Omicron BA.1 strain-neutralizing titers at 1 month after the study vaccination was reported in this outcome measure. GMTs and the corresponding 2-sided CIs were calculated by exponentiating the mean logarithm of the titers and the corresponding CIs (based on Student's t distribution).

Seroresponse was defined as achieving \>= 4-fold rise from baseline (before study vaccination). If baseline measurement is below lower limit of quantification (LLOQ), postvaccination measure of \>= 4 × LLOQ is considered seroresponse. Exact 2-sided CI, based on Clopper and Pearson method was used. Percentage of participants achieving seroresponse at 1 month was reported in this outcome measure.

GMT of SARS-CoV-2 Omicron BA.1 strain neutralizing titers before vaccination was reported in this outcome measure. GMTs and the corresponding 2-sided CIs were calculated by exponentiating the mean logarithm of the titers and the corresponding CIs (based on Student's t distribution).

Local reactions were recorded by participants in e-diary. Redness and swelling were measured and recorded in measuring device units (mdu) where, 1 mdu =0.5 centimeter (cm) and were graded as mild (greater than \[\>\] 2.0 to 5.0 cm), moderate (\>5.0 to 10.0 cm), severe (\>10.0 cm) and Grade 4 (emergency room \[ER\] visit or hospitalization for severe pain). Pain at injection site was graded as mild (did not interfere with activity), moderate (interfered with activity), severe (prevented daily activity) and Grade 4 (necrosis \[swelling\] or necrosis/exfoliative dermatitis \[redness\]). Grade 4 were classified by investigator or medically qualified person. Percentage of participants reporting local reactions after study vaccination and associated 2-sided 95% confidence interval (CI) based on Clopper and Pearson method was presented.

Systemic events were recorded in e-diary. Fever: oral temperature greater than or equal to 38.0 deg C and categorized as \>=38.0-38.4 deg C, \>38.4-38.9 deg C, \>38.9-40.0 deg C \& \>40.0 deg C. Fatigue, headache, chills, muscle pain and joint pain: mild (did not interfere with activity), moderate (some interference with activity), severe (prevented daily routine activity) and Grade 4 (ER visit or hospitalization). Vomiting: mild: 1-2 times in 24 h, moderate: \> 2 times in 24h, severe: required intravenous hydration and Grade 4: ER or hospitalization for hypotensive shock. Diarrhea: mild: 2-3 loose stools in 24h, moderate: 4-5 loose stools in 24h, severe: 6 or more loose stools in 24h and Grade 4: ER visit or hospitalization for severe diarrhea. Grade 4 were classified by investigator or medically qualified person. Exact 95% CI was based on Clopper and Pearson method.

An AE was defined as any untoward medical occurrence in a clinical study participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention. Percentage of participants reporting AEs within 1 month after study vaccination were reported in this outcome measure. Exact 2-sided CI was calculated using the Clopper and Pearson method. Only AEs collected by non-systematic assessment (i.e., excluding local reactions and systemic events) were reported in this outcome measure.

An SAE was defined as any untoward medical occurrence that at any dose resulted in death, was life-threatening; resulted in persistent disability/incapacity; constituted a congenital anomaly/birth defect; was important medical event; required inpatient hospitalization or prolongation of existing hospitalization. Exact 2-sided 95% CI was based on the Clopper and Pearson method.

GMT of SARS-CoV-2 reference-strain-neutralizing titers before vaccination was reported in this outcome measure. GMTs and the corresponding 2-sided CIs were calculated by exponentiating the mean logarithm of the titers and the corresponding CIs (based on Student's t distribution).

GMT of SARS-CoV-2 Omicron BA.4/BA.5 strain neutralizing titers before vaccination was reported in this outcome measure. GMTs and the corresponding 2-sided CIs were calculated by exponentiating the mean logarithm of the titers and the corresponding CIs (based on Student's t distribution).

GMR was calculated based on the GMT of SARS-CoV-2 Omicron BA.1 strain-neutralizing titers and reported in statistical analysis. GMTs of SARS-CoV-2 Omicron BA.1 strain neutralizing titers at Day 7 were reported in this outcome measure in descriptive data section. GMTs and the 2-sided 95% CIs were calculated by exponentiating the mean logarithm of the titers and the corresponding CIs (based on Student's t distribution). Assay results below the LLOQ were set to 0.5\*LLOQ.

GMR was calculated based on the GMT of SARS-CoV-2 Omicron reference strain-neutralizing titers and reported in statistical analysis. GMTs of SARS-CoV-2 reference strain neutralizing titers at Day 7 were reported in this outcome measure in descriptive data section. GMTs and the 2-sided 95% CIs were calculated by exponentiating the mean logarithm of the titers and the corresponding CIs (based on Student's t distribution). Assay results below the LLOQ were set to 0.5\*LLOQ.

GMR was calculated based on the GMT of SARS-CoV-2 Omicron BA.4/BA.5 strain-neutralizing titers and reported in statistical analysis. GMTs of SARS-CoV-2 Omicron BA.4/BA.5 strain neutralizing titers at Day 7 were reported in this outcome measure in descriptive data section. GMTs and the 2-sided 95% CIs were calculated by exponentiating the mean logarithm of the titers and the corresponding CIs (based on Student's t distribution). Assay results below the LLOQ were set to 0.5\*LLOQ.

GMR was calculated based on the GMT of SARS-CoV-2 Omicron BA.1 strain-neutralizing titers and reported in statistical analysis. GMTs of SARS-CoV-2 Omicron BA.1 strain neutralizing titers at 1 month were reported in this outcome measure in descriptive data section. GMTs and the 2-sided 95% CIs were calculated by exponentiating the mean logarithm of the titers and the corresponding CIs (based on Student's t distribution). Assay results below the LLOQ were set to 0.5\*LLOQ.

GMR was calculated based on the GMT of SARS-CoV-2 Omicron reference strain-neutralizing titers and reported in statistical analysis. GMTs of SARS-CoV-2 reference strain neutralizing titers at 1 month were reported in this outcome measure in descriptive data section. GMTs and the 2-sided 95% CIs were calculated by exponentiating the mean logarithm of the titers and the corresponding CIs (based on Student's t distribution). Assay results below the LLOQ were set to 0.5\*LLOQ.

GMR was calculated based on the GMT of SARS-CoV-2 Omicron reference strain-neutralizing titers and reported in statistical analysis. GMTs of SARS-CoV-2 Omicron BA.4/BA.5 strain neutralizing titers at 1 month were reported in this outcome measure in descriptive data section. GMTs and the 2-sided 95% CIs were calculated by exponentiating the mean logarithm of the titers and the corresponding CIs (based on Student's t distribution). Assay results below the LLOQ were set to 0.5\*LLOQ.

GMR was calculated based on the GMT of SARS-CoV-2 Omicron BA.1 strain-neutralizing titers and reported in statistical analysis. GMTs of SARS-CoV-2 Omicron BA.1 strain neutralizing titers at 3 months were reported in this outcome measure in descriptive data section. GMTs and the 2-sided 95% CIs were calculated by exponentiating the mean logarithm of the titers and the corresponding CIs (based on Student's t distribution). Assay results below the LLOQ were set to 0.5\*LLOQ.

GMR was calculated based on the GMT of SARS-CoV-2 Omicron reference strain-neutralizing titers and reported in statistical analysis. GMTs of SARS-CoV-2 reference strain neutralizing titers at 3 months were reported in this outcome measure in descriptive data section. GMTs and the 2-sided 95% CIs were calculated by exponentiating the mean logarithm of the titers and the corresponding CIs (based on Student's t distribution). Assay results below the LLOQ were set to 0.5\*LLOQ.

GMR was calculated based on the GMT of SARS-CoV-2 Omicron BA.4/BA.5 strain-neutralizing titers and reported in statistical analysis. GMTs of SARS-CoV-2 Omicron BA.4/BA.5 strain neutralizing titers at 3 months were reported in this outcome measure in descriptive data section. GMTs and the 2-sided 95% CIs were calculated by exponentiating the mean logarithm of the titers and the corresponding CIs (based on Student's t distribution). Assay results below the LLOQ were set to 0.5\*LLOQ.

GMR was calculated based on the GMT of SARS-CoV-2 Omicron BA.1 strain-neutralizing titers and reported in statistical analysis. GMTs of SARS-CoV-2 Omicron BA.1 strain neutralizing titers at 6 months were reported in this outcome measure in descriptive data section. GMTs and the 2-sided 95% CIs were calculated by exponentiating the mean logarithm of the titers and the corresponding CIs (based on Student's t distribution). Assay results below the LLOQ were set to 0.5\*LLOQ.

GMR was calculated based on the GMT of SARS-CoV-2 Omicron BA.1 strain-neutralizing titers and reported in statistical analysis. GMTs of SARS-CoV-2 reference strain neutralizing titers at 6 months were reported in this outcome measure in descriptive data section. GMTs and the 2-sided 95% CIs were calculated by exponentiating the mean logarithm of the titers and the corresponding CIs (based on Student's t distribution). Assay results below the LLOQ were set to 0.5\*LLOQ.

GMR was calculated based on the GMT of SARS-CoV-2 Omicron BA.1 strain-neutralizing titers and reported in statistical analysis. GMTs of SARS-CoV-2 Omicron BA.4/BA.5 strain neutralizing titers at 6 months were reported in this outcome measure in descriptive data section. GMTs and the 2-sided 95% CIs were calculated by exponentiating the mean logarithm of the titers and the corresponding CIs (based on Student's t distribution). Assay results below the LLOQ were set to 0.5\*LLOQ.

GMFR of SARS-CoV-2 Omicron BA.1 strain-neutralizing titers before vaccination to Day 7 was reported in this outcome measure. GMFR and the corresponding 2-sided CIs were calculated by exponentiating the mean logarithm of the fold rises from before vaccination and the corresponding CIs (based on the student's t distribution).

GMFR of SARS-CoV-2 reference-strain-neutralizing titers before vaccination to Day 7 was reported in this outcome measure. GMFR and the corresponding 2-sided CIs were calculated by exponentiating the mean logarithm of the fold rises from before vaccination and the corresponding CIs (based on the student's t distribution).

GMFR of SARS-CoV-2 Omicron BA.4/BA.5 strain-neutralizing titers before vaccination to Day 7 was reported in this outcome measure. GMFR and the corresponding 2-sided CIs were calculated by exponentiating the mean logarithm of the fold rises from before vaccination and the corresponding CIs (based on the student's t distribution).

GMFR of SARS-CoV-2 Omicron BA.1 strain-neutralizing titers before vaccination to 1 month was reported in this outcome measure. GMFR and the corresponding 2-sided CIs were calculated by exponentiating the mean logarithm of the fold rises from before vaccination and the corresponding CIs (based on the student's t distribution).

GMFR of SARS-CoV-2 reference-strain-neutralizing titers before vaccination to 1 month was reported in this outcome measure. GMFR and the corresponding 2-sided CIs were calculated by exponentiating the mean logarithm of the fold rises from before vaccination and the corresponding CIs (based on the student's t distribution).

GMFR of SARS-CoV-2 Omicron BA.4/BA.5 strain-neutralizing titers before vaccination to 1 month was reported in this outcome measure. GMFR and the corresponding 2-sided CIs were calculated by exponentiating the mean logarithm of the fold rises from before vaccination and the corresponding CIs (based on the student's t distribution).

GMFR of SARS-CoV-2 Omicron BA.1 strain-neutralizing titers before vaccination to 3 months was reported in this outcome measure. GMFR and the corresponding 2-sided CIs were calculated by exponentiating the mean logarithm of the fold rises from before vaccination and the corresponding CIs (based on the student's t distribution).

GMFR of SARS-CoV-2 reference-strain-neutralizing titers before vaccination to 3 months was reported in this outcome measure. GMFR and the corresponding 2-sided CIs were calculated by exponentiating the mean logarithm of the fold rises from before vaccination and the corresponding CIs (based on the student's t distribution).

GMFR of SARS-CoV-2 Omicron BA.4/BA.5 strain-neutralizing titers before vaccination to 3 months was reported in this outcome measure. GMFR and the corresponding 2-sided CIs were calculated by exponentiating the mean logarithm of the fold rises from before vaccination and the corresponding CIs (based on the student's t distribution).

GMFR of SARS-CoV-2 Omicron BA.1 strain-neutralizing titers before vaccination to 6 months was reported in this outcome measure. GMFR and the corresponding 2-sided CIs were calculated by exponentiating the mean logarithm of the fold rises from before vaccination and the corresponding CIs (based on the student's t distribution).

GMFR of SARS-CoV-2 reference-strain-neutralizing titers before vaccination to 6 months was reported in this outcome measure. GMFR and the corresponding 2-sided CIs were calculated by exponentiating the mean logarithm of the fold rises from before vaccination and the corresponding CIs (based on the student's t distribution).

GMFR of SARS-CoV-2 Omicron BA.4/BA.5 strain-neutralizing titers before vaccination to 6 months was reported in this outcome measure. GMFR and the corresponding 2-sided CIs were calculated by exponentiating the mean logarithm of the fold rises from before vaccination and the corresponding CIs (based on the student's t distribution).

Seroresponse was defined as achieving \>= 4-fold rise from baseline (before the study vaccination). If the baseline measurement is below the lower limit of quantification (LLOQ), the postvaccination measure of \>= 4 × LLOQ is considered a seroresponse. Exact 2-sided CI, based on the Clopper and Pearson method was used. Percentage of participants achieving seroresponse on Day 7 was reported in this outcome measure.

Seroresponse was defined as achieving \>= 4-fold rise from baseline (before the study vaccination). If the baseline measurement is below the lower limit of quantification (LLOQ), the postvaccination measure of \>= 4 × LLOQ is considered a seroresponse. Exact 2-sided CI, based on the Clopper and Pearson method was used. Percentage of participants achieving seroresponse on Day 7 was reported in this outcome measure.

Seroresponse was defined as achieving \>= 4-fold rise from baseline (before the study vaccination). If the baseline measurement is below the lower limit of quantification (LLOQ), the postvaccination measure of \>= 4 × LLOQ is considered a seroresponse. Exact 2-sided CI, based on the Clopper and Pearson method was used. Percentage of participants achieving seroresponse on Day 7 was reported in this outcome measure.

Seroresponse was defined as achieving \>= 4-fold rise from baseline (before the study vaccination). If the baseline measurement is below the lower limit of quantification (LLOQ), the postvaccination measure of \>= 4 × LLOQ is considered a seroresponse. Exact 2-sided CI, based on the Clopper and Pearson method was used. Percentage of participants achieving seroresponse at 1 month was reported in this outcome measure.

Seroresponse was defined as achieving \>= 4-fold rise from baseline (before the study vaccination). If the baseline measurement is below the lower limit of quantification (LLOQ), the postvaccination measure of \>= 4 × LLOQ is considered a seroresponse. Exact 2-sided CI, based on the Clopper and Pearson method was used. Percentage of participants achieving seroresponse at 1 month was reported in this outcome measure.

Seroresponse was defined as achieving \>= 4-fold rise from baseline (before the study vaccination). If the baseline measurement is below the lower limit of quantification (LLOQ), the postvaccination measure of \>= 4 × LLOQ is considered a seroresponse. Exact 2-sided CI, based on the Clopper and Pearson method was used. Percentage of participants achieving seroresponse at 1 month was reported in this outcome measure.

Seroresponse was defined as achieving \>= 4-fold rise from baseline (before the study vaccination). If the baseline measurement is below the lower limit of quantification (LLOQ), the postvaccination measure of \>= 4 × LLOQ is considered a seroresponse. Exact 2-sided CI, based on the Clopper and Pearson method was used. Percentage of participants achieving seroresponse at 3 months was reported in this outcome measure.

Seroresponse was defined as achieving \>= 4-fold rise from baseline (before the study vaccination). If the baseline measurement is below the lower limit of quantification (LLOQ), the postvaccination measure of \>= 4 × LLOQ is considered a seroresponse. Exact 2-sided CI, based on the Clopper and Pearson method was used. Percentage of participants achieving seroresponse at 3 months was reported in this outcome measure.

Seroresponse was defined as achieving \>= 4-fold rise from baseline (before the study vaccination). If the baseline measurement is below the lower limit of quantification (LLOQ), the postvaccination measure of \>= 4 × LLOQ is considered a seroresponse. Exact 2-sided CI, based on the Clopper and Pearson method was used. Percentage of participants achieving seroresponse at 3 months was reported in this outcome measure.

Seroresponse was defined as achieving \>= 4-fold rise from baseline (before the study vaccination). If the baseline measurement is below the lower limit of quantification (LLOQ), the postvaccination measure of \>= 4 × LLOQ is considered a seroresponse. Exact 2-sided CI, based on the Clopper and Pearson method was used. Percentage of participants achieving seroresponse at 6 months was reported in this outcome measure.

Seroresponse was defined as achieving \>= 4-fold rise from baseline (before the study vaccination). If the baseline measurement is below the lower limit of quantification (LLOQ), the postvaccination measure of \>= 4 × LLOQ is considered a seroresponse. Exact 2-sided CI, based on the Clopper and Pearson method was used. Percentage of participants achieving seroresponse at 6 months was reported in this outcome measure.

Seroresponse was defined as achieving \>= 4-fold rise from baseline (before the study vaccination). If the baseline measurement is below the lower limit of quantification (LLOQ), the postvaccination measure of \>= 4 × LLOQ is considered a seroresponse. Exact 2-sided CI, based on the Clopper and Pearson method was used. Percentage of participants achieving seroresponse at 6 months was reported in this outcome measure.

GMTs of full-length S-binding IgG level for lyophilized formulation in SDVs and frozen-Liquid formulation in MDVs were reported in this outcome measure as geometric mean concentration (GMCs) in descriptive data section. GMC and 95 percent (%) confidence interval (CI) were calculated by exponentiating the mean logarithm of the concentrations and the corresponding CIs (based on the Student t distribution). Assay results below the LLOQ were set to 0.5\*LLOQ. Geometric mean ratio (GMR) was calculated as ratios of GMCs of BNT162b2 30 mcg lyophilized SDV and frozen-liquid MDV. GMR are reported in the statistical analysis section.

Local reactions were collected by the participant using an electronic diary. Local reactions included redness, swelling, and pain at injection site after each vaccination.

Local reactions were collected by the participant using an electronic diary. Local reactions included redness, swelling, and pain at injection site after each vaccination.

Systemic events were reported using an electronic diary. Fever was defined as temperature \>=38.0 degree Celsius (C). Systemic events including fever, fatigue, headache, chills, new or worsened muscle pain, new or worsened joint pain, vomiting, and diarrhea after Dose 1 were reported.

Systemic events were reported using an electronic diary. Fever was defined as temperature \>=38.0 degree C. Systemic events including fever, fatigue, headache, chills, new or worsened muscle pain, new or worsened joint pain, vomiting, and diarrhea after Dose 2 were reported.

An AE was any untoward medical occurrence in a participant who received investigational product without regard to possibility of causal relationship. SAE was an AE resulting in any of the following outcomes or deemed significant for any other reason: death; initial or prolonged inpatient hospitalization; life-threatening experience (immediate risk of dying); persistent or significant disability/incapacity; congenital anomaly/birth defect or that was considered to be an important medical event. AEs included all non-SAEs and SAEs. Only AEs collected by non-systematic assessment (i.e. excluding local reactions and systemic events) were reported in this outcome measure.

Geometric mean concentration of full-length S-binding IgG level for individual US lots (US lots 1, 2, and 3) was determined and reported in the descriptive section. Assay results below the lower limit of quantitation (LLOQ) were set to 0.5\*LLOQ. GMRs were reported in the statistical analysis section and was calculated as ratio of Geometric Mean Concentrations (GMCs) of individual US Lots BNT162b2 30 mcg: US Lot 1, BNT162b2 30 mcg: US Lot 2 and BNT162b2 30 mcg: US Lot 3.

Geometric mean concentration of full-length S-binding IgG level for EU lot and pooled US lots (BNT162b2 30 mcg: US Lot 1, BNT162b2 30 mcg: US Lot 2 and BNT162b2 30 mcg: US Lot 3 reporting arm) were determined and reported in the descriptive section. Assay results below the LLOQ were set to 0.5\*LLOQ. GMRs were reported in the statistical analysis section and was calculated as ratios of GMCs of BNT162b2 30 mcg: EU Lot and pooled US Lots (BNT162b2 30 mcg: US Lot 1, BNT162b2 30 mcg: US Lot 2 and BNT162b2 30 mcg: US Lot 3 reporting arm).

Geometric mean titer for SARS-CoV-2 neutralizing titers for 20 mcg dose and 30 mcg dose of US Lot 1 was determined and reported in the descriptive section. GMTs and 2-sided 95% CIs were calculated by exponentiating the least square (LS) mean of the titers and corresponding CIs based on linear regression model. Assay results below the LLOQ were set to 0.5\*LLOQ. GMRs were reported in the statistical analysis section and were calculated as the ratio of geometric mean titer of the 20-mcg dose (US Lot 1) to the geometric mean titer of the 30 mcg dose (US Lot 1).

Local reactions were collected by the participant using an electronic diary. Local reactions included redness, swelling, and pain at injection site after Dose 1. Redness, swelling, and pain at injection site after Dose 1 were reported.

Local reactions were collected by the participant using an electronic diary. Local reactions included redness, swelling, and pain at injection site after Dose 2. Redness, swelling, and pain at injection site after Dose 2 were reported.

Local reactions were collected by the participant using an electronic diary. Local reactions included redness, swelling, and pain at injection site after each vaccination. Redness, swelling, and pain at injection site after any dose were reported.

Local reactions were collected by the participant using an electronic diary. Local reactions included redness, swelling, and pain at injection site after Dose 3. Redness, swelling, and pain at injection site after Dose 3 were reported.

Systemic events were reported using an electronic diary. Fever was defined as temperature \>=38.0 degree Celsius (C) and categorized as \>=38.0 to 38.4 C; \>38.4 to 38.9 C; \>38.9 to 40.0 C; \>40.0 C. Systemic events including fever, fatigue, headache, chills, new or worsened muscle pain, new or worsened joint pain, vomiting, diarrhea, and use of antipyretic/analgesic medication after Dose 1 were reported.

Systemic events were reported using an electronic diary. Fever was defined as temperature \>=38.0 C and categorized as \>=38.0 to 38.4 C; \>38.4 to 38.9 C; \>38.9 to 40.0 C; \>40.0 C. Systemic events including fever, fatigue, headache, chills, new or worsened muscle pain, new or worsened joint pain, vomiting, diarrhea, and use of antipyretic/analgesic medication after Dose 2 were reported.

Systemic events were reported using an electronic diary. Fever was defined as temperature \>=38.0 C and categorized as \>=38.0 to 38.4 C; \>38.4 to 38.9 C; \>38.9 to 40.0 C; \>40.0 C. Systemic events including fever, fatigue, headache, chills, new or worsened muscle pain, new or worsened joint pain, vomiting, diarrhea, and use of antipyretic/analgesic medication after any dose were reported.

Systemic events were reported using an electronic diary. Fever was defined as temperature \>=38.0 C and categorized as \>=38.0 to 38.4 C; \>38.4 to 38.9 C; \>38.9 to 40.0 C; \>40.0 C. Systemic events including fever, fatigue, headache, chills, new or worsened muscle pain, new or worsened joint pain, vomiting, diarrhea, and use of antipyretic/analgesic medication after Dose 3 were reported.

An AE was any untoward medical occurrence in a participant who received investigational product without regard to possibility of causal relationship. SAE was an AE resulting in any of the following outcomes or deemed significant for any other reason: death; initial or prolonged inpatient hospitalization; life-threatening experience (immediate risk of dying); persistent or significant disability/incapacity; congenital anomaly or that was considered to be an important medical event.

An AE was any untoward medical occurrence in a participant who received investigational product without regard to possibility of causal relationship. SAE was an AE resulting in any of the following outcomes or deemed significant for any other reason: death; initial or prolonged inpatient hospitalization; life-threatening experience (immediate risk of dying); persistent or significant disability/incapacity; congenital anomaly or that was considered to be an important medical event.

GMTs and 2-sided 95% CIs were calculated by exponentiating the mean logarithm of the titers and the corresponding CIs (based on the Student t distribution). Assay results below the LLOQ were set to 0.5 × LLOQ.

GMTs and 2-sided 95% CIs were calculated by exponentiating the mean logarithm of the titers and the corresponding CIs (based on the Student t distribution). Assay results below the LLOQ were set to 0.5 × LLOQ.

GMTs and 2-sided 95% CIs were calculated by exponentiating the mean logarithm of the titers and the corresponding CIs (based on the Student t distribution). Assay results below the LLOQ were set to 0.5 × LLOQ.

GMTs and 2-sided 95% CIs were calculated by exponentiating the mean logarithm of the titers and the corresponding CIs (based on the Student t distribution). Assay results below the LLOQ were set to 0.5 × LLOQ.

GMTs and 2-sided 95% CIs were calculated by exponentiating the mean logarithm of the titers and the corresponding CIs (based on the Student t distribution). Assay results below the LLOQ were set to 0.5 × LLOQ.

GMTs and 2-sided 95% CIs were planned to be calculated by exponentiating the mean logarithm of the titers and the corresponding CIs (based on the Student t distribution).

GMTs and 2-sided 95% CIs were planned to be calculated by exponentiating the mean logarithm of the titers and the corresponding CIs (based on the Student t distribution).

GMTs and 2-sided 95% CIs were calculated by exponentiating the mean logarithm of the titers and the corresponding CIs (based on the Student t distribution). Assay results below the LLOQ were set to 0.5 × LLOQ.

GMTs and 2-sided 95% CIs were calculated by exponentiating the mean logarithm of the titers and the corresponding CIs (based on the Student t distribution). Assay results below the LLOQ were set to 0.5 × LLOQ.

GMTs and 2-sided 95% CIs were calculated by exponentiating the mean logarithm of the titers and the corresponding CIs (based on the Student t distribution). Assay results below the LLOQ were set to 0.5 × LLOQ.

GMCs were calculated by exponentiating the mean logarithm of the concentrations and the corresponding CIs (based on the Student t distribution). Assay results below the LLOQ were set to 0.5\*LLOQ.

GMCs were calculated by exponentiating the mean logarithm of the concentrations and the corresponding CIs (based on the Student t distribution). Assay results below the LLOQ were set to 0.5\*LLOQ.

GMCs were calculated by exponentiating the mean logarithm of the concentrations and the corresponding CIs (based on the Student t distribution). Assay results below the LLOQ were set to 0.5\*LLOQ.

GMCs were calculated by exponentiating the mean logarithm of the concentrations and the corresponding CIs (based on the Student t distribution). Assay results below the LLOQ were set to 0.5\*LLOQ.

GMCs were calculated by exponentiating the mean logarithm of the concentrations and the corresponding CIs (based on the Student t distribution). Assay results below the LLOQ were set to 0.5\*LLOQ.

GMFRs were defined as ratios of the geometric mean concentration of IgG at 1 week after Dose 3 to the geometric mean concentration of IgG at 1 month after dose 2. GMFRs were calculated by exponentiating the mean logarithm of fold rises and the corresponding CIs (based on the Student t distribution). Assay results below the LLOQ were set to 0.5\*LLOQ.

GMFRs were defined as ratios of the geometric mean concentration of IgG at 1 month after Dose 3 to the geometric mean concentration of IgG at 1 month after dose 2. GMFRs were calculated by exponentiating the mean logarithm of fold rises and the corresponding CIs (based on the Student t distribution). Assay results below the LLOQ were set to 0.5\*LLOQ.

GMFRs were defined as ratios of the geometric mean concentration of IgG at 1 week after Dose 3 to the geometric mean concentration of IgG before dose 3. GMFRs were calculated by exponentiating the mean logarithm of fold rises and the corresponding CIs (based on the Student t distribution). Assay results below the LLOQ were set to 0.5\*LLOQ.

GMFRs were defined as ratios of the geometric mean concentration of IgG at 1 month after Dose 3 to the geometric mean concentration of IgG before dose 3. GMFRs were calculated by exponentiating the mean logarithm of fold rises and the corresponding CIs (based on the Student t distribution). Assay results below the LLOQ were set to 0.5\*LLOQ.

GMFRs were defined as ratios of the geometric mean titers of SARS-CoV-2 reference-strain at 1 week after Dose 3 to the geometric mean titers of SARS-CoV-2 reference-strain at 1 month after dose 2. GMFRs were calculated by exponentiating the mean logarithm of fold rises and the corresponding CIs (based on the Student t distribution). Assay results below the LLOQ were set to 0.5\*LLOQ.

GMFRs were defined as ratios of the geometric mean titers of SARS-CoV-2 reference-strain at 1 month after Dose 3 to the geometric mean titers of SARS-CoV-2 reference-strain at 1 month after dose 2. GMFRs were calculated by exponentiating the mean logarithm of fold rises and the corresponding CIs (based on the Student t distribution). Assay results below the LLOQ were set to 0.5\*LLOQ.

GMFRs were defined as ratios of the geometric mean titers of SARS-CoV-2 reference-strain at 1 week after Dose 3 to the geometric mean titers of SARS-CoV-2 reference-strain before dose 3. GMFRs were calculated by exponentiating the mean logarithm of fold rises and the corresponding CIs (based on the Student t distribution). Assay results below the LLOQ were set to 0.5\*LLOQ.

GMFRs were defined as ratios of the geometric mean titers of SARS-CoV-2 reference-strain at 1 month after Dose 3 to the geometric mean titers of SARS-CoV-2 reference-strain before dose 3. GMFRs were calculated by exponentiating the mean logarithm of fold rises and the corresponding CIs (based on the Student t distribution). Assay results below the LLOQ were set to 0.5\*LLOQ.

GMFRs were defined as ratios of the geometric mean titers of SARS-CoV-2 B.1.351-strain at 1 week after Dose 3 to the geometric mean titers of SARS-CoV-2 B.1.351-strain at 1 month after dose 2. GMFRs were planned to be calculated by exponentiating the mean logarithm of fold rises and the corresponding CIs (based on the Student t distribution).

GMFRs were defined as ratios of the geometric mean titers of SARS-CoV-2 B.1.351-strain at 1 month after Dose 3 to the geometric mean titers of SARS-CoV-2 B.1.351-strain at 1 month after dose 2. GMFRs were planned to be calculated by exponentiating the mean logarithm of fold rises and the corresponding CIs (based on the Student t distribution).

GMFRs were defined as ratios of the geometric mean titers of SARS-CoV-2 B.1.351-strain at 1 week after Dose 3 to the geometric mean titers of SARS-CoV-2 B.1.351-strain before dose 3. GMFRs were calculated by exponentiating the mean logarithm of fold rises and the corresponding CIs (based on the Student t distribution). Assay results below the LLOQ were set to 0.5\*LLOQ.

GMFRs were defined as ratios of the geometric mean titers of SARS-CoV-2 B.1.351-strain at 1 month after Dose 3 to the geometric mean titers of SARS-CoV-2 B.1.351-strain before dose 3. GMFRs were calculated by exponentiating the mean logarithm of fold rises and the corresponding CIs (based on the Student t distribution). Assay results below the LLOQ were set to 0.5\*LLOQ.

Seroresponse was defined as greater than equal to (\>=) 4-fold increase from baseline (before Dose 1 in primary study) to the specified time point. If the baseline measurement was below LLOQ, a post vaccination measurement of \>=4\*LLOQ was considered a seroresponse. Exact 2-sided 95% CI was based on the Clopper and Pearson method.

Seroresponse was defined as \>=4-fold increase from baseline (before Dose 1 in primary study) to the specified time point. If the baseline measurement was below LLOQ, a post vaccination measurement of \>=4\*LLOQ was considered a seroresponse. Exact 2-sided 95% CI was based on the Clopper and Pearson method.

Seroresponse was defined as \>=4-fold increase from baseline (before Dose 1 in primary study) to the specified time point. If the baseline measurement was below LLOQ, a post vaccination measurement of \>=4\*LLOQ was considered a seroresponse. Exact 2-sided 95% CI was based on the Clopper and Pearson method.

Seroresponse was defined as \>=4-fold increase from baseline (before Dose 1 in primary study) to the specified time point. If the baseline measurement was below LLOQ, a post vaccination measurement of \>=4\*LLOQ was considered a seroresponse. Exact 2-sided 95% CI was based on the Clopper and Pearson method.

Seroresponse was defined as \>=4-fold increase from baseline (before Dose 1 in primary study) to the specified time point.

Seroresponse was defined as \>=4-fold increase from baseline (before Dose 1 in primary study) to the specified time point.

Seroresponse was defined as \>=4-fold increase from baseline (before Dose 1 in primary study) to the specified time point.

Seroresponse was defined as \>=4-fold increase from baseline (before Dose 1 in primary study) to the specified time point.

Local reactions: pain at injection site, redness and swelling were recorded by participants in an electronic diary (e-diary) or as adverse events (AEs) in the case report form (CRF). Redness and swelling were recorded in measuring device units (mdu) (range: 1 to 21), 1 mdu =0.5 centimeter (cm) and were graded as mild (greater than \[\>\] 2.0 to 5.0 cm), moderate (\>5.0 to 10.0 cm), severe (\>10.0 cm) and Grade 4 (necrosis \[swelling\] and necrosis or exfoliative dermatitis \[redness\]). Pain at injection site was graded as mild (did not interfere with activity), moderate (interfered with activity), severe (prevented daily activity) and Grade 4 (emergency room \[ER\] visit or hospitalization for severe pain at injection site). Grade 4 local reactions were classified by investigator or medically qualified person.

Systemic events were recorded by participants in an e-diary or as AEs in the CRF. Fever: defined as oral temperature more than or equal to (\>=38) degree Celsius (C) and categorized as \>= 38.0 to 38.4 degree C, \>38.4 to 38.9 degree C, \>38.9 to 40.0 degree C and \>40.0 degree C. Fatigue, headache, chills, new or worsened muscle pain and joint pain were graded as: mild (did not interfere with activity), moderate (some interference with activity), severe (prevented daily routine activity). Vomiting: mild: 1-2 times in 24 hours (h), moderate: \>2 times in 24h, severe: required intravenous (IV) hydration. Diarrhea was graded as: mild: 2-3 loose stools in 24h, moderate: 4-5 loose stools in 24h, severe: 6 or more loose stools in 24h. Grade 4 for all events except fever: ER visit/hospitalization. Grade 4 systemic events were classified by investigator or medically qualified person.

An AE was defined as any untoward medical occurrence in a clinical study participant, temporally associated with use of study intervention, whether or not considered related to study intervention. A serious AE (SAE) was defined as any untoward medical occurrence at any dose that resulted in any of the following outcomes: death; life-threatening; required inpatient hospitalization or prolongation of existing hospitalization; persistent or significant disability/incapacity; congenital anomaly/birth defect, any other event pre-specified in protocol of the study; or considered as an important medical event. AEs included both SAEs and all non-SAEs. Only AEs collected by non-systematic assessment (i.e., excluding local reactions and systemic events) were reported in this outcome measure.

An AE was defined as any untoward medical occurrence in a clinical study participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention. A SAE was defined as any untoward medical occurrence at any dose that resulted in any of the following outcomes: death; life-threatening; required inpatient hospitalization or prolongation of existing hospitalization; persistent or significant disability/incapacity; congenital anomaly/birth defect, any other event pre-specified in protocol of the study; or considered as an important medical event.

GMTs and 2-sided 95 percentage (%) confidence interval (CIs) were calculated by exponentiating the mean logarithm of the titers and the corresponding CIs (based on the Student t distribution). Assay results below the lower limit of quantitation (LLOQ) were set to 0.5\*LLOQ.

GMTs and 2-sided 95% CIs were calculated by exponentiating the mean logarithm of the titers and the corresponding CIs (based on the Student t distribution). Assay results below the LLOQ were set to 0.5\*LLOQ.

GMFRs were defined as geometric mean ratios of the results after vaccination to the results before vaccination. GMFR and 2-sided 95% CI were calculated by exponentiating the mean logarithm of fold rises and the corresponding CIs (based on the Student t distribution). Assay results below the LLOQ were set to 0.5\*LLOQ.

GMFRs were defined as geometric mean ratios of the results after vaccination to the results before vaccination. GMFR and 2-sided 95% CI were calculated by exponentiating the mean logarithm of fold rises and the corresponding CIs (based on the Student t distribution). Assay results below the LLOQ were set to 0.5\*LLOQ.

Seroresponse was defined as achieving \>= 4-fold rise from baseline (before the study vaccination). If the baseline measurement was below the LLOQ, the postvaccination assay result of \>= 4\* LLOQ was considered a seroresponse.

Seroresponse was defined as achieving \>= 4-fold rise from baseline (before the study vaccination). If the baseline measurement was below the LLOQ, the postvaccination assay result of \>= 4\* LLOQ was considered a seroresponse.

Local reactions: pain at injection site, redness and swelling were recorded by participants in an e-diary or as AEs in the CRF. Redness and swelling were recorded in mdu (range:1 to 21), 1 mdu= 0.5 cm and were graded as mild (\>2.0 to 5.0 cm), moderate (\>5.0 to 10.0 cm), severe (\>10.0 cm) and Grade 4 (necrosis \[swelling\] and necrosis or exfoliative dermatitis \[redness\]). Pain at injection site was graded as mild (did not interfere with activity), moderate (interfered with activity), severe (prevented daily activity) and Grade 4 (ER visit or hospitalization for severe pain at injection site). Grade 4 local reactions were classified by investigator or medically qualified person.

Systemic events were recorded by participants in an e-diary or as AEs in the CRF. Fever: defined as oral temperature \>=38 degree C and categorized as \>= 38.0 to 38.4 degree C, \>38.4 to 38.9 degree C, \>38.9 to 40.0 degree C and \>40.0 degree C. Fatigue, headache, chills, new or worsened muscle pain and joint pain were graded as: mild (didn't interfere with activity), moderate (some interference with activity), severe (prevented daily routine activity). Vomiting: mild: 1-2 times in 24h, moderate: \>2 times in 24h, severe: required IV hydration. Diarrhea were graded as: mild: 2-3 loose stools in 24h, moderate: 4-5 loose stools in 24h, severe: 6 or more loose stools in 24h. Grade 4 for all events except fever: ER visit/hospitalization. Grade 4 systemic events were classified by investigator or medically qualified person.

An AE was defined as any untoward medical occurrence in a clinical study participant, temporally associated with use of study intervention, whether or not considered related to study intervention. A SAE was defined as any untoward medical occurrence at any dose that resulted in any of the following outcomes: death; life-threatening; required inpatient hospitalization or prolongation of existing hospitalization; persistent or significant disability/incapacity; congenital anomaly/birth defect, any other event pre-specified in protocol of the study; or considered as an important medical event. AEs included both SAEs and all non-SAEs. Only AEs collected by non-systematic assessment (i.e., excluding local reactions and systemic events) were reported in this outcome measure.

An AE was defined as any untoward medical occurrence in a clinical study participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention. A SAE was defined as any untoward medical occurrence at any dose that resulted in any of the following outcomes: death; life-threatening; required inpatient hospitalization or prolongation of existing hospitalization; persistent or significant disability/incapacity; congenital anomaly/birth defect, any other event pre-specified in protocol of the study; or considered as an important medical event.

GMTs / GMRs and 2-sided 95% CIs were calculated by exponentiating the least square (LS) means / difference of LS means and the corresponding CIs based on analysis of log-transformed assay results using a linear regression model with baseline assay results (log scale), age and vaccine group as covariates. Assay results below the LLOQ were set to 0.5\*LLOQ. GMT was reported in descriptive section and GMR was reported in statistical analysis section

Seroresponse was defined as achieving \>=4-fold rise from baseline (before the study vaccination). If the baseline measurement was below the LLOQ, the postvaccination assay result of \>= 4\* LLOQ was considered a seroresponse. Percentage of participants with seroresponse were reported in descriptive section and difference in percentage of participants with seroresponse in SSB: All Age Groups (Vaccine Naive)- SSA: All Age Groups (Vaccine Experienced Control) were reported in statistical analysis section.

Local reactions: pain at injection site, redness and swelling were recorded by participants in an e-diary or as AEs in the CRF. Redness and swelling were recorded in mdu (range:1 to 21), 1 mdu= 0.5 cm and were graded as mild (\>2.0 to 5.0 cm), moderate (\>5.0 to 10.0 cm), severe (\>10.0 cm) and Grade 4 (necrosis \[swelling\] and necrosis or exfoliative dermatitis \[redness\]). Pain at injection site was graded as mild (did not interfere with activity), moderate (interfered with activity), severe (prevented daily activity) and Grade 4 (ER visit or hospitalization for severe pain at injection site). Grade 4 local reactions were classified by investigator or medically qualified person.

Systemic events were recorded by participants in an e-diary or as AEs in the CRF. Fever: defined as oral temperature \>=38 degree C and categorized as \>= 38.0 to 38.4 degree C, \>38.4 to 38.9 degree C, \>38.9 to 40.0 degree C and \>40.0 degree C. Fatigue, headache, chills, new or worsened muscle pain and joint pain were graded as: mild (didn't interfere with activity), moderate (some interference with activity), severe (prevented daily routine activity). Vomiting: mild: 1-2 times in 24h, moderate: \>2 times in 24h, severe: required IV hydration. Diarrhea were graded as: mild: 2-3 loose stools in 24h, moderate: 4-5 loose stools in 24h, severe: 6 or more loose stools in 24h. Grade 4 for all events except fever: ER visit/hospitalization. Grade 4 systemic events were classified by investigator or medically qualified person.

An AE was defined as any untoward medical occurrence in a clinical study participant, temporally associated with use of study intervention, whether or not considered related to study intervention. A SAE was defined as any untoward medical occurrence at any dose that resulted in any of the following outcomes: death; life-threatening; required inpatient hospitalization or prolongation of existing hospitalization; persistent or significant disability/incapacity; congenital anomaly/birth defect, any other event pre-specified in protocol of the study; or considered as an important medical event. AEs included both SAEs and all non-SAEs. Only AEs collected by non-systematic assessment (i.e., excluding local reactions and systemic events) were reported in this outcome measure.

An AE was defined as any untoward medical occurrence in a clinical study participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention. A SAE was defined as any untoward medical occurrence at any dose that resulted in any of the following outcomes: death; life-threatening; required inpatient hospitalization or prolongation of existing hospitalization; persistent or significant disability/incapacity; congenital anomaly/birth defect, any other event pre-specified in protocol of the study; or considered as an important medical event.

Local reactions: pain at injection site, redness and swelling were recorded by participants in an e-diary or as AEs in the CRF. Redness and swelling were recorded in mdu (range:1 to 21), 1 mdu= 0.5 cm and were graded as mild (\>2.0 to 5.0 cm), moderate (\>5.0 to 10.0 cm), severe (\>10.0 cm) and Grade 4 (necrosis \[swelling\] and necrosis or exfoliative dermatitis \[redness\]). Pain at injection site was graded as mild (did not interfere with activity), moderate (interfered with activity), severe (prevented daily activity) and Grade 4 (ER visit or hospitalization for severe pain at injection site). Grade 4 local reactions were classified by investigator or medically qualified person.

Systemic events were recorded by participants in an e-diary or as AEs in the CRF. Fever: defined as oral temperature \>=38 deg C and categorized as \>= 38.0-38.4 deg C, \>38.4-38.9 deg C, \>38.9-40.0 deg C and \>40.0 deg C. Fatigue, headache, chills, new or worsened muscle pain and joint pain: mild (didn't interfere with activity), moderate (some interference with activity), severe (prevented daily routine activity). Vomiting: mild: 1-2 times in 24h, moderate: \>2 times in 24h, severe: required IV hydration. Diarrhea: mild: 2-3 loose stools in 24h, moderate: 4-5 loose stools in 24h, severe: 6 or more loose stools in 24h. Grade 4 for all events except fever: ER visit/hospitalization. Grade 4 events were classified by investigator or medically qualified person.

An AE was defined as any untoward medical occurrence in a clinical study participant, temporally associated with use of study intervention, whether or not considered related to study intervention. A SAE was defined as any untoward medical occurrence at any dose that resulted in any of the following outcomes: death; life-threatening; required inpatient hospitalization or prolongation of existing hospitalization; persistent or significant disability/incapacity; congenital anomaly/birth defect, any other event pre-specified in protocol of the study; or considered as an important medical event. AEs included both SAEs and all non-SAEs. Only AEs collected by non-systematic assessment (i.e., excluding local reactions and systemic events) were reported in this outcome measure.

An AE was defined as any untoward medical occurrence in a clinical study participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention. A SAE was defined as any untoward medical occurrence at any dose that resulted in any of the following outcomes: death; life-threatening; required inpatient hospitalization or prolongation of existing hospitalization; persistent or significant disability/incapacity; congenital anomaly/birth defect, any other event pre-specified in protocol of the study; or considered as an important medical event.

GMTs and 2-sided 95% CIs were calculated by exponentiating the mean logarithm of the titers and the corresponding CIs (based on the Student t distribution). Assay results below the LLOQ were set to 0.5\*LLOQ.

GMFRs were defined as geometric mean ratios of the results after vaccination to the results before vaccination. GMFRs and 2-sided 95% CIs were calculated by exponentiating the mean logarithm of fold rises and the corresponding CIs (based on the Student t distribution). Assay results below the LLOQ were set to 0.5\*LLOQ in the analysis.

Seroresponse was defined as achieving a \>=4-fold rise from baseline (before the study vaccination). If the baseline measurement was below the LLOQ, a postvaccination assay result \>=4 \*LLOQ is considered a seroresponse.

GMTs and 2-sided 95% CIs were calculated by exponentiating the mean logarithm of the titers and the corresponding CIs (based on the Student t distribution). Assay results below the LLOQ were set to 0.5\*LLOQ.

GMFRs were defined as geometric mean ratios of the results after vaccination to the results before vaccination. GMFRs and 2-sided 95% CIs were calculated by exponentiating the mean logarithm of fold rises and the corresponding CIs (based on the Student t distribution). Assay results below the LLOQ were set to 0.5\*LLOQ in the analysis.

Seroresponse was defined as achieving a \>=4-fold rise from baseline (before the study vaccination). If the baseline measurement was below the LLOQ, a postvaccination assay result \>=4 \*LLOQ is considered a seroresponse.

Local reactions of any grade are reported. Local reactions were graded using criteria based on the US FDA Guidance for Industry "Toxicity Grading Scale for Healthy Adult and Adolescent Volunteers Enrolled in Preventive Vaccine Clinical Trials"; the guidance uses the Grades 1 (mild), 2 (moderate), 3 (severe), and 4 (potentially life-threatening). The reporting of systemic reactions was based on the participant's assessments collected in the electronic diary (e-diary) or mapped from the adverse event case report form from Day 1 to Day 7 after each IMP dose. For Erythema/redness and Induration/swelling, the reported size had to be at least 2.5 cm to be deemed as a local reaction. Local reactions with a size less than 2.5 cm are not included in the analysis. Subjects in Cohort 9 did not receive a vaccination and are not included in this analysis.

Systemic reactions of any grade are reported. Systemic reactions were graded using criteria based on the guidance given in the US FDA Guidance for Industry "Toxicity Grading Scale for Healthy Adult and Adolescent Volunteers Enrolled in Preventive Vaccine Clinical Trials"; the guidance uses the Grades 1 (mild), 2 (moderate), 3 (severe), and 4 (potentially life-threatening). The reporting of systemic reactions was based on the participant's assessments collected in the e-diary or mapped from the adverse event case report form from Day 1 to Day 7 after each IMP dose. For Fever, the reported oral temperature had to be ≥38.0°C to be deemed as a systemic event. Oral temperature less than 38.0°C are not included in the analysis. Subjects in Cohort 9 did not receive a vaccination and are not included in this analysis.

An AE is defined as TEAE if the event onset date and time is after the first IMP dose (if the event was absent before the first administration of the IMP) or worsened after the first IMP dose (if the event was present before the first administration of the IMP). In the event of an incomplete onset date, the event is considered as treatment-emergent unless the partial onset date information or complete or partial end date confirms the onset date or the event end prior to the first dose of IMP. Percentages for dose 1, dose 2, dose 3 and overall summaries are based upon the number of participants who received the respective IMP dose.

An SAE was any untoward medical occurrence that, at any dose: resulted in death; was life-threatening; required inpatient hospitalization or prolongation of existing hospitalization; resulted in persistent disability/ incapacity; was a congenital anomaly/birth defect and/or was another important medical event. SAEs from dose 1 up to 6 months post last IMP dose are presented. MedDRA (version 26.1) coding dictionary applied. An SAE is defined as TESAE if the event onset date and time is after the first IMP dose (if the event was absent before the first administration of the IMP) or worsened after the first IMP dose (if the event was present before the first administration of the IMP). In the event of an incomplete onset date, the event is considered as treatment-emergent unless the partial onset date information or complete or partial end date confirms the onset date or the event end prior to the first dose of IMP.

GMRs and 2-sided 95% CIs were calculated by exponentiating the difference of least square means and corresponding CIs based on the analysis of logarithmically transformed neutralizing titers using a linear regression model with terms of age, sex, and vaccine group. The overall number of participants analyzed represents the number of participants with valid and determinate assay results for B.1.1.7 and reference strain respectively at the given dose/sampling time point within the specified window. GMR data are presented below as per the primary endpoint defined in the protocol. GMTs for the individual arms (from which GMR was derived) were secondary endpoints and are presented in outcome measure 22. GMR = Geometric mean ratio; NT = neutralizing titers

GMRs and 2-sided 95% CIs were calculated by exponentiating the difference of least square means and corresponding CIs based on the analysis of logarithmically transformed neutralizing titers using a linear regression model with terms of age, sex, and group. The overall number of participants analyzed represents the number of participants with valid and determinate assay results for B.1.617.2 and reference strain respectively at the given dose/sampling time point within the specified window. GMR data are presented below as per the primary endpoint defined in the protocol. GMTs for the individual arms (from which GMR was derived) were secondary endpoints and are presented in outcome measure 22. GMR = Geometric mean ratio; NT = neutralizing titers

GMRs and 2-sided 95% CIs were calculated by exponentiating the difference of least square means and corresponding CIs based on the analysis of logarithmically transformed neutralizing titers using a linear regression model with terms of age, sex, and group. The overall number of participants analyzed represents the number of participants with valid and determinate assay results for B.1.617.2 and reference strain respectively at the given dose/sampling time point within the specified window. GMR data are presented below as per the primary endpoint defined in the protocol. GMTs for the individual arms (from which GMR was derived) were secondary endpoints and are presented in outcome measure 24.

Seroresponse was defined as a ≥4-fold rise in neutralizing titer from baseline. For subjects with a baseline titer less than the lower limit of quantitation (\<LLOQ), seroresponse was defined as a post-vaccination titer of ≥4× LLOQ. Adjusted difference was estimated using minimum risk weights and stratified by sex and age group (18 to 55 years, 56 to 85 years), expressed as a percentage. Associated 2-sided 95% CI based on the Newcombe method with minimum risk weights for the difference in proportions. Difference in seroresponse data are presented below as per the primary endpoint defined in the protocol. Seroresponses for the individual arms (from which the difference was derived) were secondary endpoints and are presented in outcome measure 23.

Seroresponse was defined as a ≥4-fold rise in neutralizing titer from baseline. For subjects with a baseline titer less than the lower limit of quantitation (\<LLOQ), seroresponse was defined as a post-vaccination titer of ≥4× LLOQ. Adjusted difference was estimated using minimum risk weights and stratified by sex and age group (18 to 55 years, 56 to 85 years), expressed as a percentage. Associated 2-sided 95% CI based on the Newcombe method with minimum risk weights for the difference in proportions. Difference in seroresponse data are presented below as per the primary endpoint defined in the protocol. Seroresponses for the individual arms (from which the difference was derived) were secondary endpoints and are presented in outcome measure 23.

Seroresponse was defined as a ≥4-fold rise in neutralizing titer from baseline. For subjects with a baseline titer less than the lower limit of quantitation (\<LLOQ), seroresponse was defined as a post-vaccination titer of ≥4× LLOQ. Adjusted difference was estimated using minimum risk weights and stratified by sex and age group (18 to 55 years, 56 to 85 years), expressed as a percentage. Associated 2-sided 95% CI based on the Newcombe method with minimum risk weights for the difference in proportions. Difference in seroresponse data are presented below as per the primary endpoint defined in the protocol. Seroresponses for the individual arms (from which the difference was derived) were secondary endpoints and are presented in outcome measure 25.

Cohort B6 aimed to generate data to support a 2-dose primary regimen of alpha-delta multivalent BNT162b2 vaccine in SARS-CoV-2 naïve, unvaccinated individuals. The population recruited in Cohort B6, while complying with the inclusion criterium of no known history SARS-CoV-2 infection, were retrospectively seropositive for SARS-CoV-2 by planned N-binding antibody assessment of baseline samples. While the cohort was COVID-19 vaccine-naïve, it was not SARS-CoV-2-naïve as needed to match the control group (C4591001/NCT04368728). Procedurally, submission of a protocol amendment was not possible. However, the Statistical Analysis Plan was amended to describe that the non-inferiority analysis could not be performed according to the protocol. Control participants were not selected as planned; therefore, data were not available to calculate the GMR. Available GMT data for the 17 Cohort B6 participants without evidence of infection were analyzed and are presented in Outcome Measure 28.

Cohort B6 aimed to generate data to support a 2-dose primary regimen of alpha-delta multivalent BNT162b2 vaccine in SARS-CoV-2 naïve, unvaccinated individuals. The population recruited in Cohort B6, while complying with the inclusion criterium of no known history SARS-CoV-2 infection, were retrospectively seropositive for SARS-CoV-2 by planned N-binding antibody assessment of baseline samples. While the cohort was COVID-19 vaccine-naïve, it was not SARS-CoV-2-naïve as needed to match the control group (C4591001/NCT04368728). Procedurally, submission of a protocol amendment was not possible. However, the Statistical Analysis Plan was amended to describe that the non-inferiority analysis could not be performed according to the protocol. Control participants were not selected as planned; therefore, data were not available to calculate the GMR. Available GMT data for the 17 Part B Cohort 6 participants without evidence of infection were analyzed and are presented in Outcome Measure 28.

Cohort B6 aimed to generate data to support a 2-dose primary regimen of alpha-delta multivalent BNT162b2 vaccine in SARS-CoV-2 naïve, unvaccinated individuals. The population recruited in Cohort B6, while complying with the inclusion criterium of no known history SARS-CoV-2 infection, were retrospectively seropositive for SARS-CoV-2 by planned N-binding antibody assessment of baseline samples. While the cohort was COVID-19 vaccine-naïve, it was not SARS-CoV-2-naïve as needed to match the control group (C4591001/NCT04368728). Procedurally, submission of a protocol amendment was not possible. However, the Statistical Analysis Plan was amended to describe that non-inferiority analysis could not be performed according to the protocol. Control participants were not selected as planned; therefore, data were not available to calculate difference in SR. Available SR data for the 17 Part B Cohort 6 participants without evidence of infection were analyzed and presented in Outcome Measure 31.

Cohort B6 aimed to generate data to support a 2-dose primary regimen of alpha-delta multivalent BNT162b2 vaccine in SARS-CoV-2 naïve, unvaccinated individuals. The population recruited in Cohort B6, while complying with the inclusion criterium of no known history SARS-CoV-2 infection, were retrospectively seropositive for SARS-CoV-2 by planned N-binding antibody assessment of baseline samples. While the cohort was COVID-19 vaccine-naïve, it was not SARS-CoV-2-naïve as needed to match the control group (C4591001/NCT04368728). Procedurally, submission of a protocol amendment was not possible. However, the Statistical Analysis Plan was amended to describe that the non-inferiority analysis could not be performed according to the protocol. Control participants were not selected as planned; therefore data were not available to calculate difference in SR. Available SR data for the 17 Part B Cohort 6 participants without evidence of infection were analyzed and presented in Outcome Measure 31.

GMR of reference strain NT 3 weeks (3W) after one dose (PD1) of BNT162b2 (B.1.1.7 + B.1.617.2) in COVID-19 vaccine-naïve participants with evidence of prior infection to the reference strain NT 1 month after two doses of BNT162b2 in participants without evidence of infection (COVID-19 Vaccine-naïve Participants) from the Phase III trial C4591001 (NCT04368728). GMTs and 2-sided 95% CIs were calculated by exponentiating the mean logarithm of the titers and corresponding CIs (based on the Student t distribution). Assay results below LLOQ were set to 0.5 × LLOQ. GMTs of NTs are presented in the descriptive data section of this outcome measure. GMRs and 2-sided 95% CIs were calculated by exponentiating the difference of LS means and corresponding CIs based on the analysis of logarithmically transformed neutralizing titers using a linear regression model with terms of age, sex, and group. GMR data are presented in the statistical analysis section.

The difference in SRs to the reference strain NT 3 weeks after one dose of BNT162b2 (B.1.1.7 + B.1.617.2) in COVID-19 vaccine-naïve participants with evidence of prior infection to the reference strain NT 1 month after two doses of BNT162b2 in participants without evidence of infection from the Phase III trial C4591001 (NCT04368728). SR was defined as achieving a ≥4-fold rise from baseline. If the baseline measurement was below the LLOQ, a post-vaccination assay result ≥4 × LLOQ was considered a SR. SR to the reference strain NTs are presented in the descriptive data section of this outcome measure. Adjusted difference in proportions was estimated using minimum risk weights and stratified by sex and age group (18 to 55 years, 56 to 85 years), expressed as a percentage. 2-Sided CI was based on the Newcombe method with minimum risk weights for the difference in proportions. Difference in SR data are presented in the statistical analysis section.

GMRs and 2-sided 95% CIs were calculated by exponentiating the difference of least square means and corresponding CIs based on the analysis of logarithmically transformed neutralizing titers using a linear regression model with terms of age and number of prior doses. The overall number of participants analyzed represents the number of participants with valid and determinate assay results for B.1.1.529.1 at the given dose/sampling time point within the specified window. GMR data are presented below as per the primary endpoint defined in the protocol. GMTs for the individual arms (from which the difference was derived) were secondary endpoints and are presented in outcome measure 32.

SR was defined as a ≥4-fold rise in neutralizing titer from baseline. For participants with a baseline titer less than the lower limit of quantitation (\<LLOQ), SR was defined as a post-vaccination titer of ≥4× LLOQ. SR to the reference strain NTs are presented in the descriptive data section of this outcome measure. Adjusted difference was estimated using minimum risk weights and stratified by sex and age group (18 to 55 years, 56 to 85 years), expressed as a percentage. Associated 2-sided 95% CI were based on the Newcombe method with minimum risk weights for the difference in proportions. Difference in SR data are presented in the statistical analysis section.

Pain at injection site, redness \& swelling were recorded by participants in an electronic diary (e-diary). Redness \& swelling were measured \& recorded in measuring devise units (range 1 to 21) then converted to cm. 1 measuring device unit = 0.5 cm \& graded as mild: \> 2.0 to 5.0 cm, moderate: \> 5.0 to 10.0 cm, severe: \> 10.0 cm, grade 4 (potentially life threatening): necrosis or exfoliative dermatitis (redness) \& necrosis (swelling). Pain at injection site was graded as mild: did not interfere with daily activity, moderate: interfered with daily activity, severe: prevented daily activity \& grade 4 (potentially life threatening): emergency room visit or hospitalization for severe pain. Grade 4 reactions were classified by the investigator or medically qualified person. Reactions reported as adverse events in the case report form within 7 days after the study vaccination were also included in the analysis. Exact 2-sided 95% confidence interval (CI) was based on Clopper \& Pearson method.

Pain at injection site, redness \& swelling were recorded by participants in an e-diary. Redness \& swelling were measured \& recorded in measuring devise units (range 1 to 21) then converted to cm. 1 measuring device unit = 0.5 cm \& graded as mild: \> 2.0 to 5.0 cm, moderate: \> 5.0 to 10.0 cm, severe: \> 10.0 cm, grade 4 (potentially life threatening): necrosis or exfoliative dermatitis (redness) \& necrosis (swelling). Pain at injection site was graded as mild: did not interfere with daily activity, moderate: interfered with daily activity, severe: prevented daily activity \& grade 4 (potentially life threatening): emergency room visit or hospitalization for severe pain. Grade 4 reactions were classified by the investigator or medically qualified person. Reactions reported as adverse events (AEs) in the case report form (CRF) within 7 days after the study vaccination were also included in the analysis. Exact 2-sided 95% CI was based on the Clopper \& Pearson method.

Systemic events were recorded by participants in an e-diary. Fever was oral temperature \>= 38 degree Celsius (°C) \& categorized as \>=38.0 to 38.4 °C, \>38.4 to 38.9 °C, \>38.9 to 40.0 °C \& \>40.0 °C. Fatigue, headache, chills, new or worsened muscle pain \& new or worsened joint pain were graded mild: did not interfere with activity, moderate: some interference with activity \& severe: prevented daily routine activity. Vomiting was graded mild: 1 to 2 times in 24 hours (h), moderate: \>2 times in 24h \& severe: required intravenous hydration. Diarrhea was graded mild: 2 to 3 loose stools in 24h, moderate: 4 to 5 loose stools in 24h \& severe: 6 or more loose stools in 24h. For all systemic events except fever, Grade 4= emergency room visit or hospitalization. Grade 4 events were classified by the investigator/medically qualified person. Systemic events reported as AEs in the CRF within 7 days after vaccination were also included in analysis. Exact 95% CI was based on Clopper \& Pearson method.

Systemic events were recorded by participants in an e-diary. Fever was oral temperature \>= 38 °C \& categorized as \>=38.0 to 38.4 °C, \>38.4 to 38.9 °C, \>38.9 to 40.0 °C \& \>40.0 °C. Fatigue, headache, chills, new or worsened muscle pain \& new or worsened joint pain were graded mild: did not interfere with activity, moderate: some interference with activity \& severe: prevented daily routine activity. Vomiting was graded mild: 1 to 2 times in 24 h, moderate: \>2 times in 24 h \& severe: required intravenous hydration. Diarrhea was graded mild: 2 to 3 loose stools in 24 h, moderate: 4 to 5 loose stools in 24 h \& severe: 6 or more loose stools in 24 h. For all systemic events except fever, Grade 4= emergency room visit or hospitalization. Grade 4 events were classified by the investigator/medically qualified person. Systemic events reported as AEs in the CRF within 7 days after vaccination were also included in analysis. Exact 95% CI was based on Clopper \& Pearson method.

An AE was any untoward medical occurrence in a participant temporally associated with the use of study intervention, whether or not considered related to the study intervention. Exact 2-sided 95% CI was based on the Clopper and Pearson method. Only AEs collected by non-systematic assessment (i.e., excluding local reactions and systemic events) were reported in this outcome measure.

An SAE was defined as any untoward medical occurrence that at any dose resulted in death, was life-threatening; resulted in persistent disability/incapacity; constituted a congenital anomaly/birth defect; was important medical event; required inpatient hospitalization or prolongation of existing hospitalization. Exact 2-sided 95% CI was based on the Clopper and Pearson method.

GMR of SARS-CoV-2 neutralizing titers in pregnant women to those in nonpregnant women from study C4591001 (NCT04368728) for evaluable immunogenicity population without evidence of prior SARS-CoV-2 infection up to 1 month after Dose 2 was reported in this outcome measure. Geometric mean titer (GMT) and 2-sided 95% CIs were calculated by exponentiating mean logarithm of titers and corresponding CIs (based on student t distribution) and was reported in descriptive section. GMR was reported in statistical analysis section of this outcome measure. Evaluable immunogenicity population included all participants who were eligible and randomized, received 2 doses of vaccine to which they were randomized, with Dose 2 received within predefined window (19-42 days, inclusive, after Dose 1); had at least 1 valid immunogenicity result within an appropriate window 1 month after Dose 2 (28-42 days, inclusive, after Dose 2); and had no other important protocol deviations as determined by the clinician.

GMR of SARS-CoV-2 neutralizing titers in pregnant women to those in nonpregnant women from study C4591001 (NCT04368728) for evaluable immunogenicity population with and without evidence of prior SARS-CoV-2 infection was reported in this outcome measure. GMT and 2-sided 95% CIs were calculated by exponentiating the mean logarithm of the titers and the corresponding CIs (based on the student t distribution) and was reported in the descriptive section. GMR was reported in the statistical analysis section. Evaluable immunogenicity population included all participants who were eligible and randomized, received 2 doses of the vaccine to which they were randomized, with Dose 2 received within the predefined window (19-42 days, inclusive, after Dose 1); had at least 1 valid immunogenicity result within an appropriate window 1 month after Dose 2 (28-42 days, inclusive, after Dose 2); and had no other important protocol deviations as determined by the clinician.