Local reactions included pain, redness and swelling at the injection site, 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; 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: greater than (\>) 5.0 cm to 10.0 cm; severe: \> 10 cm.

Local reactions included pain, redness and swelling at the injection site, recorded by participants in an e-diary. Pain at injection site was graded as mild: did not interfere with activity; moderate: interfered with activity; 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: 2.5 cm to 5.0 cm; moderate: \> 5.0 cm to 10.0 cm; severe: \> 10 cm.

Local reactions included pain, redness and swelling at the injection site, recorded by participants in an e-diary. Pain at injection site was graded as mild: did not interfere with activity; moderate: interfered with activity; 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: 2.5 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, chills, new/worsened muscle pain and new/worsened 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, 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, chills, new/worsened muscle pain and new/worsened 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, chills, new/worsened muscle pain and new/worsened joint pain. These were recorded by participants in an e-diary. Fever defined as oral temperature \>=38.0 deg C and categorized as mild: \>=38.0 to 38.4 deg C, moderate: \>38.4 to 38.9 deg C, severe: \>38.9 to 40.0 deg C. Vomiting categorized as mild: 1-2 times in 24h; moderate: \>2 times in 24h; severe: required 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, chills, new/worsened muscle pain and new/worsened 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, chills, new/worsened muscle pain and new/worsened joint pain. These were recorded by participants in an e-diary. Fever defined as oral temperature \>=38.0 deg C and categorized as mild: \>=38.0 to 38.4 deg C, moderate: \>38.4 to 38.9 deg C, severe: \>38.9 to 40.0 deg C. Vomiting categorized as mild: 1-2 times in 24h; moderate: \>2 times in 24h; severe: required 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, chills, new/worsened muscle pain and new/worsened 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.

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.

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. 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 included.

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.

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.

GMTs and associated 2-sided 95% CIs are reported as descriptive data. GMRs and associated 2-sided 95% CIs are reported in statistical analysis section of this outcome measure. GMR was the ratio of RSV subgroup A (RSV A) or RSV subgroup B (RSV B) neutralizing GMTs in the combination RSVpreF + qIRV group to that in the sequential-administration RSVpreF group.

GMTs and associated 2-sided 95% CIs are reported as descriptive data. GMRs and associated 2-sided 95% CIs are reported in statistical analysis section of this outcome measure. GMR was the ratio of each strain neutralizing GMTs in the combination RSVpreF + qIRV group to that in the sequential-administration RSVpreF group. The analysis was performed on the influenza strains: H1N1 A/Sydney, H3N2 A/Darwin, B/Austria, and B/Phuket.