Describe prompted local reactions following investigational product administration

Describe prompted systemic events following investigational product administration

Describe AEs occurring through 1 month following administration of investigational product

Describe SAEs through 2 months following administration of investigational product

Demonstrate that the immune responses to RSVpreF in this study participant are similar to those in Study C3671013 Japanese older adults

Local reactions included pain at injection site, redness and swelling, recorded by participants in an electronic diary (e-diary). Pain at injection site was graded as mild: did not interfere with activity; moderate: interfered with activity and severe: prevented daily activity. Redness and swelling were measured and recorded in measuring device units, where 1 measuring device unit =0.5 centimeter (cm). Redness and swelling were graded as mild: \>2.5 cm to 5.0 cm; moderate: \>5.0 cm to 10.0 cm; severe: \>10 cm.

Systemic events included fever, fatigue, headache, vomiting, nausea, diarrhea, muscle pain and joint pain. These were recorded by participants in an e-diary. Fever defined as oral temperature \>=38.0 degrees Celsius (deg C) and categorized as mild: \>=38.0 to 38.4 deg C, moderate: \>38.4 to 38.9 deg C and severe: \>38.9 to 40.0 deg C. Vomiting categorized as mild: 1-2 times in 24 hours (h); moderate: \>2 times in 24h; severe: required intravenous (IV) hydration. Diarrhea categorized as mild: 2-3 loose stools in 24h; moderate: 4-5 loose stools in 24h; severe: 6 or more loose stools in 24h. Headache, fatigue, nausea, muscle pain and joint pain were categorized as mild: didn't interfere with activity; moderate: some interference with activity; severe: prevented daily routine activity.

An AE was defined as any untoward medical occurrence in a participant temporally associated with the use of study intervention, whether or not considered related to the study intervention. Only AEs collected by non-systematic assessment (i.e. excluding local reactions and systemic events) were included. AEs included both serious and all non-serious adverse events.

A NDCMC was defined as a disease or medical condition that was not identified prior to study start and was expected to be persistent or otherwise long-lasting in its effects. Newly diagnosed chronic medical condition did not include illnesses considered to be temporary conditions.

An AE was defined as any untoward medical occurrence in a clinical study participant, temporally associated with the use of study intervention. An SAE was defined as any untoward medical occurrence that, at any dose, met one or more of the following criteria - resulted in death, was life-threatening, required inpatient hospitalization or prolongation of existing hospitalization, resulted in persistent or significant disability/incapacity, was a congenital anomaly/birth defect and was a suspected transmission via a Pfizer product of an infectious agent, pathogenic or non-pathogenic and other important medical event were included in this outcome measure.

In this outcome measure, GMTs for RSV A and RSV B neutralizing titers (NTs) are reported. In statistical section, GMT ratio estimated by the ratio of the GMTs for RSV A and RSV B serum NTs at 1 month after vaccination with RSVpreF in current study C3671023 participants to that in study C3671013 adults \>=60 years of age, is reported. GMTs and the corresponding 2-sided CIs were calculated by exponentiating the mean logarithm of the titers and the corresponding CIs (based on Student t distribution).

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

Local reactions included pain at injection site, redness and swelling, recorded by participants in an e-diary. Pain at injection site was graded as mild: did not interfere with activity; moderate: interfered with activity and severe: prevented daily activity. Redness and swelling were measured and recorded in measuring device units, where 1 measuring device unit=0.5 cm. Redness and swelling were graded as mild: \> 2.0 cm to 5.0 cm; moderate: \> 5.0 cm to 10.0 cm and severe: \> 10 cm.

Local reactions included pain at injection site, redness and swelling, recorded by participants in an e-diary. Pain at injection site was graded as mild: did not interfere with activity; moderate: interfered with activity and severe: prevented daily activity. Redness and swelling were measured and recorded in measuring device units, where 1 measuring device unit = 0.5 cm. Redness and swelling were graded as mild: \>2.0 cm to 5.0 cm; moderate: \>5.0 cm to 10.0 cm and severe: \>10 cm.

Systemic events included fever, fatigue, headache, vomiting, nausea, diarrhea, muscle pain and joint pain. These were recorded by participants in an e-diary. Fever defined as oral temperature \>=38.0 degrees Celsius (deg C) and categorized as mild: \>=38.0 to 38.4 deg C, moderate: \>38.4 to 38.9 deg C and severe: \>38.9 to 40.0 deg C. Vomiting categorized as mild: 1-2 times in 24 hours (h); moderate: \>2 times in 24h; severe: required intravenous (IV) hydration. Diarrhea categorized as mild: 2-3 loose stools in 24h; moderate: 4-5 loose stools in 24h; severe: 6 or more loose stools in 24h. Headache, fatigue, nausea, muscle pain and joint pain were categorized as mild: didn't interfere with activity; moderate: some interference with activity; severe: prevented daily routine activity.

Systemic events included fever, fatigue, headache, vomiting, nausea, diarrhea, muscle pain and joint pain. These were recorded by participants in an e-diary. Fever defined as oral temperature \>=38.0 degrees Celsius (deg C) and categorized as mild: \>=38.0 to 38.4 deg C, moderate: \>38.4 to 38.9 deg C and severe: \>38.9 to 40.0 deg C. Vomiting categorized as mild: 1-2 times in 24 hours (h); moderate: \>2 times in 24h; severe: required intravenous (IV) hydration. Diarrhea categorized as mild: 2-3 loose stools in 24h; moderate: 4-5 loose stools in 24h; severe: 6 or more loose stools in 24h. Headache, fatigue, nausea, muscle pain and joint pain were categorized as mild: didn't interfere with activity; moderate: some interference with activity; severe: prevented daily routine activity.

An AE was defined as any untoward medical occurrence in a participant temporally associated with the use of study intervention, whether or not considered related to the study intervention. Only AEs collected by non-systematic assessment (i.e. excluding local reactions and systemic events) were included. AEs included both serious and all non-serious adverse events.

A NDCMC was defined as a disease or medical condition that was not identified prior to study start and was expected to be persistent or otherwise long-lasting in its effects. Newly diagnosed chronic medical condition did not include illnesses considered to be temporary conditions.

An AE was defined as any untoward medical occurrence in a clinical study participant, temporally associated with the use of study intervention. An SAE was defined as any untoward medical occurrence that, at any dose, met one or more of the following criteria - resulted in death, was life-threatening, required inpatient hospitalization or prolongation of existing hospitalization, resulted in persistent or significant disability/incapacity, was a congenital anomaly/birth defect and was a suspected transmission via a Pfizer product of an infectious agent, pathogenic or non-pathogenic and other important medical event were included in this outcome measure.

GMT of RSV A and RSV B before vaccination were reported in this outcome measure. Assay results below the lower limit of quantification (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).

GMT of RSV A and RSV B before vaccination were reported in this outcome measure. Assay results below the lower limit of quantification (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).

GMT of RSV A and RSV B before vaccination were reported in this outcome measure. Assay results below the lower limit of quantification (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).