Local reactions were recorded by participants in an electronic diary (e-diary). Local reactions included redness, swelling and pain at injection site. Redness and swelling were graded as mild: greater than (\>) 2.0 to 5.0 centimeter (cm), moderate: \>5.0 to 10.0 cm, severe: \>10.0 cm, grade 4 (potentially life threatening): necrosis or exfoliative dermatitis (redness) and 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 and 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. Local reactions reported as adverse events (AEs) in the case report form within 7 days after the study vaccination were also reported.

Systemic events were recorded by participants in an e-diary. Fever was oral temperature greater than or equal to (\>=) 38 degree Celsius (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 was graded as mild: 1 to 2 times in 24 hours (h), moderate: \>2 times in 24h and severe: required intravenous hydration. Diarrhea was graded as mild: 2 to 3 loose stools in 24h, moderate: 4 to 5 loose stools in 24h and 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 reported.

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. Results excluded local reactions and systemic events data.

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 an AE that resulted in death, was life-threatening, resulted in persistent disability/incapacity; constituted a congenital anomaly/birth defect; was important medical event, medical event was judged by investigator; required inpatient hospitalization or prolongation of existing hospitalization.

GMTs and the corresponding 2-sided confidence intervals (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 lower limit of quantification (LLOQ) were set to 0.5\*LLOQ.

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).

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). Assay results below the LLOQ were set to 0.5\*LLOQ.

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). Assay results below the LLOQ were set to 0.5\*LLOQ.

GMFR from before study vaccination to 1 month after study vaccination for each strain-specific neutralizing titer was reported in this endpoint. GMFRs and 2-sided 95% CIs were calculated by exponentiating mean logarithm of fold rises and corresponding CIs (based on student-t distribution). Assay results below lower limit of quantitation (LLOQ) were set to 0.5\*LLOQ in analysis.

GMFR from before study vaccination to 1 month after study vaccination for each strain-specific neutralizing titer was reported in this endpoint. GMFRs and 2-sided 95% CIs were calculated by exponentiating mean logarithm of fold rises and corresponding CIs (based on student-t distribution). Assay results below LLOQ were set to 0.5\*LLOQ in analysis.

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

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

Local reactions were recorded by participants in an e-diary. Local reactions included redness, swelling and pain at injection site. Redness and swelling were 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) and 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 and 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. Local reactions reported as AEs in the case report form within 7 days after the study vaccination were also reported.

Systemic events were recorded by participants in an e-diary. Fever was oral temperature \>= 38 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 was graded as mild: 1 to 2 times in 24h, moderate: \>2 times in 24h and severe: required intravenous hydration. Diarrhea was graded as mild: 2 to 3 loose stools in 24h, moderate: 4 to 5 loose stools in 24h and 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 or medically qualified person. Systemic events reported as AEs in the CRF within 7 days after vaccination were also reported.

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. Results excluded local reactions and systemic events data.

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 an AE that 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.

Local reactions were recorded by participants in an e-diary. Local reactions included redness, swelling and pain at injection site. Redness and swelling were 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) and 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 and 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. Local reactions reported as AEs in the case report form within 7 days after the study vaccination were also reported.

Systemic events were recorded by participants in an e-diary. Fever was oral temperature \>= 38 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 was graded as mild: 1 to 2 times in 24 h, moderate: \>2 times in 24h and severe: required intravenous hydration. Diarrhea was graded as mild: 2 to 3 loose stools in 24h, moderate: 4 to 5 loose stools in 24h and 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 reported.

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. Results excluded local reactions and systemic events data.

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 an AE that 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.

Model based GMT of OMI BA.4/BA.5 NTs induced by BNT162b2 Bivalent 30mcg groups of study C4591044 Cohort 2/3 combined and BNT162b2 30mcg of study C4591031 \[NCT04955626\] Substudy E among participants \>55 years are reported as descriptive data. GMTs and 95% CIs were calculated by exponentiating least square (LS) means and corresponding CI based on analysis of logarithmically transformed NT using a linear regression model with terms of baseline NT (log scale) and vaccine group. Assay results below LLOQ were set to 0.5\*LLOQ. Model based geometric mean ratio (GMR) are reported in statistical section: OMI BA.4/BA.5 NTs induced 1 month post BNT162b2 Bivalent vaccination in study C4591044 to 1 month post BNT162b2 vaccination in study C4591031 \[NCT04955626\] among participants \>55 years. Outcome measure was planned per protocol to be analyzed in participants of Cohort 2 (Group 4) + Cohort 3 (Group 2) of C4591044 and BNT162b2 experienced participants of study C4591031 \[NCT04955626\] (control arm).

Seroresponse: achieving \>=4-fold rise in NTs from baseline (before study vaccination). If baseline measurement was below LLOQ, postvaccination measure of \>= 4\*LLOQ was considered seroresponse. Percentage of participants with seroresponse to OMI BA.4/BA.5 for BNT162b2 Bivalent 30 mcg in Study C4591044 \[NCT05472038\] Cohort 2/3 combined and BNT162b2 30 mcg in Study C4591031 \[NCT04955626\] Substudy E among participants \>55 years of age are presented as descriptive data. Adjusted difference in seroresponse rate to OMI BA.4/BA.5 between BNT162b2 Bivalent \[WT/OMI BA.4/BA.5\] 30 mcg 1 month after vaccination in study C4591044 and 1 month after BNT162b2 vaccination in study C4591031 \[NCT04955626\] among participants \>55 years of age is reported in statistical section. Outcome measure was planned per protocol to be analyzed in participants from Cohort 2 (Group 4) + Cohort 3 (Group 2) and control arm of BNT162b2 experienced participants \>55 years of age from study C4591031 \[NCT04955626\] Substudy E.

Model based GMT of OMI BA.4/BA.5 NTs induced by BNT162b2 Bivalent 30 mcg groups of study C4591044 \[NCT05472038\] Cohort 2/3 combined in participants 18-55 years of age compared to participants \>55 years of age are presented as descriptive data. GMTs and 2-sided 95% CIs were calculated by exponentiating LS means and corresponding CIs based on analysis of logarithmically transformed NT using a linear regression model with terms of baseline NT (log scale) and vaccine group. Assay results below LLOQ were set to 0.5\*LLOQ. Model based GMR: OMI BA.4/BA.5 NTs induced 1 month after BNT162b2 Bivalent vaccination in study C4591044 among participants 18-55 years of age compared to participants \>55 years of age is reported in statistical section. The outcome measure was planned per protocol to be analyzed in participants combined from Cohort 2 (Group 2) + Cohort 3 (Group 1) and Cohort 2 (Group 4) + Cohort 3 (Group 2).

Seroresponse was defined as achieving \>= 4-fold rise in NTs from baseline (before the study vaccination). If the baseline measurement was below the LLOQ, the postvaccination measure of \>= 4\*LLOQ was considered a seroresponse. Percentage of participants with seroresponse to OMI BA.4/BA.5 for BNT162b2 Bivalent 30 mcg in Study C4591044 \[NCT05472038\] Cohort 2/3 combined in participants 18-55 years of age compared to participants \>55 years of age are presented as descriptive data. Adjusted difference in seroresponse rate to OMI BA.4/BA.5 between BNT162b2 Bivalent \[WT/OMI BA.4/BA.5\] 30 mcg 1 month after vaccination in study C4591044 in participants 18-55 years of age compared to participants \>55 years of age is reported in statistical section. The outcome measure was planned per protocol to be analyzed in participants combined from Cohort 2 (Group 2) + Cohort 3 (Group 1) and Cohort 2 (Group 4) + Cohort 3 (Group 2).

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). This outcome measure was planned per protocol to be analyzed in participants from Cohort 2 and control arms of BNT162b2 Bivalent (WT/OMI BA.1) experienced participants from study C4591031 \[NCT04955626\] Substudy E.

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). This outcome measure was planned per protocol to be analyzed in participants from Cohort 2 and control arms of BNT162b2 experienced participants from study C4591031 \[NCT04955626\] Substudy E.

GMFR from before the study vaccination to 1 month after the study vaccination for each strain-specific neutralizing titer was reported in this outcome measure. 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. This outcome measure was planned per protocol to be analyzed in participants from Cohort 2 and control arms of BNT162b2 experienced participants from study C4591031 \[NCT04955626\] Substudy E.

Seroresponse was defined as achieving \>= 4-fold rise in NTs from baseline (before the study vaccination). If the baseline measurement was below the LLOQ, the postvaccination measure of \>= 4\*LLOQ was considered a seroresponse. Percentage of participants with seroresponse to OMI BA.4/BA.5 for BNT162b2 Bivalent 30 and 60 mcg in Study C4591044 \[NCT05472038\] Cohort 2 and BNT162b2 30 mcg in Study C4591031 \[NCT04955626\] Substudy E are presented as descriptive data. This outcome measure was planned per protocol to be analyzed in participants from Cohort 2 and control arms of BNT162b2 experienced participants 18-55 years of age and \>55 years of age from study C4591031 \[NCT04955626\] Substudy E.

Local reactions were recorded by participants in an e-diary. Local reactions included redness, swelling and pain at injection site. Redness and swelling were 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) and 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 and 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. Local reactions reported as AEs in the case report form within 7 days after the study vaccination were also reported.

Systemic events were recorded by participants in an e-diary. Fever was oral temperature \>= 38 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 was graded as mild: 1 to 2 times in 24h, moderate: \>2 times in 24h and severe: required intravenous hydration. Diarrhea was graded as mild: 2 to 3 loose stools in 24h, moderate: 4 to 5 loose stools in 24h and 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 or medically qualified person. Systemic events reported as AEs in the CRF within 7 days after vaccination were also reported.

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. Results excluded local reactions and systemic events data.

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 an AE that 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.

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).

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 from before study vaccination to 1 month after study vaccination for each strain-specific neutralizing titer was reported in this endpoint. GMFRs and 2-sided 95% CIs were calculated by exponentiating mean logarithm of fold rises and corresponding CIs (based on student-t distribution). Assay results below LLOQ were set to 0.5\*LLOQ in analysis.

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