A Study to Learn About New COVID-19 RNA Vaccine Candidates in COVID-19 Vaccine-Experienced Healthy Individuals

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.

Time frame: From before the study vaccination to 1 month after the study vaccination

Population: EIP: randomized participants who received intervention to which they were randomized, 1 valid, determinate immunogenicity result from blood sample collected 28-42 days post vaccination, no important protocol deviations. Analysis performed in participants without evidence of infection up to 1 month post vaccination. Here, ''Overall Number of Participants Analyzed'' signifies participants evaluable for this outcome measure; ''Number Analyzed'' signifies participants evaluable for specified rows.

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.

Time frame: At baseline (before study vaccination)

Population: Evaluable immunogenicity population (EIP): randomized participants who received intervention to which they were randomized, 1 valid, determinate immunogenicity result from blood sample collected 28-42 days post vaccination, no important protocol deviations. Analysis performed in participants without evidence of infection up to 1 month post vaccination. Overall Number of Participants Analyzed= participants evaluable for outcome measure; Number Analyzed= participants evaluable for specified rows.

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.

Time frame: From before the study vaccination to 1 month after the study vaccination

Population: EIP: all eligible randomized/assigned participants who received study intervention to which they were randomized/assigned, had at least 1 valid, determinate immunogenicity result from blood sample collected within 28-42 days after study vaccination, had no other important protocol deviations as determined by clinician. Analysis was performed in participants with or without evidence of infection up to 1 month post study vaccination. ''Number Analyzed''= participants evaluable for specified rows.

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.

Time frame: 1 month after the study vaccination

Population: EIP: all eligible randomized/assigned participants who received study intervention to which they were randomized/assigned, had at least 1 valid, determinate immunogenicity result from blood sample collected within 28-42 days after study vaccination, had no other important protocol deviations as determined by clinician. Analysis was performed in participants with or without evidence of infection up to 1 month post study vaccination. ''Number Analyzed'' = participants evaluable for specified rows.

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.

Time frame: 1 month after the study vaccination

Population: EIP: randomized participants who received intervention to which they were randomized, 1 valid, determinate immunogenicity result from blood sample collected 28-42 days post vaccination, no important protocol deviations. Analysis performed in participants without evidence of infection up to 1 month post vaccination. Here, ''Overall Number of Participants Analyzed'' signifies participants evaluable for this outcome measure; ''Number Analyzed'' signifies participants evaluable for specified rows.

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).

Time frame: At baseline (before study vaccination)

Population: EIP: all eligible randomized/assigned participants who received study intervention to which they were randomized/assigned, had at least 1 valid, determinate immunogenicity result from blood sample collected within 28-42 days after study vaccination, had no other important protocol deviations as determined by clinician. Analysis was performed in participants with or without evidence of infection up to 1 month post study vaccination. ''Number Analyzed'' =participants evaluable for specified rows.

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.

Time frame: From Day 1 to Day 7 after study vaccination

Population: Safety population included all participants who received the study intervention and where appropriate informed consent was obtained.

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.

Time frame: From Day 1 to Day 7 after study vaccination

Population: Safety population included all participants who received the study intervention and where appropriate informed consent was obtained.

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.

Time frame: From study vaccination on Day 1 through 1 month after study vaccination

Population: Safety population included all participants who received the study intervention and where appropriate informed consent was obtained.

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.

Time frame: From study vaccination on Day 1 through 6 months after study vaccination

Population: Safety population included all participants who received the study intervention and where appropriate informed consent was obtained.

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.

Time frame: 1 month after the study vaccination

Population: EIP: all eligible randomized/assigned participants who received study intervention to which they were randomized/assigned, had at least 1 valid, determinate immunogenicity result from blood sample collected within 28-42 days after study vaccination, had no other important protocol deviations as determined by clinician. Analysis was performed in participants with or without evidence of infection up to 1 month post study vaccination. ''Number Analyzed'' = participants evaluable for specified rows.

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.

Time frame: 1 month after the study vaccination

Population: EIP: randomized participants who received intervention to which they were randomized, 1 valid, determinate immunogenicity result from blood sample collected 28-42 days post vaccination, no important protocol deviations. Analysis performed in participants without evidence of infection up to 1 month post vaccination. Here, ''Overall Number of Participants Analyzed'' signifies participants evaluable for this outcome measure; ''Number Analyzed'' signifies participants evaluable for specified rows.

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.

Time frame: From before the study vaccination to 1 month after the study vaccination

Population: EIP: eligible, randomized participants received study intervention to which they were randomized, 1 valid, determinate immunogenicity result from blood sample collected within 28-42 days post study vaccination, no important protocol deviations. Analysis performed in participants with or without evidence of infection up to 1 month post study vaccination. Overall Number of Participants Analyzed= participants evaluable for outcome measure; Number Analyzed= participants evaluable for specified rows.

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.

Time frame: 1 month after the study vaccination

Population: EIP: eligible, randomized participants received study intervention to which they were randomized, 1 valid, determinate immunogenicity result from blood sample collected within 28-42 days post study vaccination, no important protocol deviations. Analysis performed in participants with or without evidence of infection up to 1 month post study vaccination. Here, ''Number Analyzed'' signifies participants evaluable for specified rows.

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.

Time frame: At baseline (before study vaccination)

Population: EIP: eligible, randomized participants received study intervention to which they were randomized, 1 valid, determinate immunogenicity result from blood sample collected within 28-42 days post study vaccination, no important protocol deviations. Analysis performed in participants with or without evidence of infection up to 1 month post study vaccination. Overall Number of Participants Analyzed= participants evaluable for outcome measure; Number Analyzed= participants evaluable for specified rows.

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.

Time frame: From Day 1 to Day 7 after study vaccination

Population: Safety population included all participants who received the study intervention and where appropriate informed consent was obtained. Here, Overall Number of Participants Analyzed signifies participants evaluable for this outcome measure and ''Number Analyzed'' signifies participants evaluable for the specified rows. 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).

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.

Time frame: From Day 1 to Day 7 after study vaccination

Population: Safety population included all participants who received the study intervention and where appropriate informed consent was obtained. Here, Overall Number of Participants Analyzed signifies participants evaluable for this outcome measure and 'Number Analyzed' signifies participants evaluable for the specified rows. 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).

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.

Time frame: From study vaccination through 1 month after study vaccination

Population: Safety population included all participants who received the study intervention and where appropriate informed consent was obtained. 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).

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.

Time frame: From study vaccination through 6 months after study vaccination

Population: Safety population included all participants who received the study intervention and where appropriate informed consent was obtained. 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).

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.

Time frame: From Day 1 to Day 7 after study vaccination

Population: Safety population included all participants who received the study intervention and where appropriate informed consent was obtained. Here, Overall Number of Participants Analyzed signifies participants evaluable for this outcome measure and ''Number Analyzed'' signifies participants evaluable for the specified rows.

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.

Time frame: From Day 1 to Day 7 after study vaccination

Population: Safety population included all participants who received the study intervention and where appropriate informed consent was obtained. Here, Overall Number of Participants Analyzed signifies participants evaluable for 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. Results excluded local reactions and systemic events data.

Time frame: From study vaccination through 1 month after study vaccination

Population: Safety population included all participants who received the study intervention and where appropriate informed consent was obtained.

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.

Time frame: From study vaccination through 6 months after study vaccination

Population: Safety population included all participants who received the study intervention and where appropriate informed consent was obtained.

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.

Time frame: 1 month after the study vaccination

Population: EIP: eligible, randomized participants received study intervention to which they were randomized, 1 valid, determinate immunogenicity result from blood sample collected within 28-42 days post study vaccination, no important protocol deviations. Analysis performed in participants with or without evidence of infection up to 1 month post study vaccination. Overall Number of Participants Analyzed= participants evaluable for outcome measure; Number Analyzed= participants evaluable for specified rows.

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.

Time frame: From before the study vaccination to 1 month after study vaccination

Population: EIP included all assigned/ randomized participants who received study intervention to which they were randomized/assigned, had at least 1 valid and determinate immunogenicity result from blood sample collected within 28-42 days post the vaccination and had no other important protocol deviations. Analysis was performed in participants with or without evidence of infection up to 1 month post study vaccination.

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).

Time frame: 1 month after the study vaccination

Population: EIP included all assigned/ randomized participants who received study intervention to which they were randomized/assigned, had at least 1 valid and determinate immunogenicity result from blood sample collected within 28-42 days post the vaccination and had no other important protocol deviations. Analysis was performed in participants with or without evidence of infection up to 1 month post study vaccination.

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).

Time frame: At baseline (before study vaccination)

Population: EIP included all assigned/ randomized participants who received study intervention to which they were randomized/assigned, had at least 1 valid and determinate immunogenicity result from blood sample collected within 28-42 days post the vaccination and had no other important protocol deviations. Analysis was performed in participants with or without evidence of infection up to 1 month post study vaccination.

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.

Time frame: From Day 1 to Day 7 after study vaccination

Population: Safety population included all participants who received the study intervention and where appropriate informed consent was obtained. Here, Overall Number of Participants Analyzed signifies participants evaluable for this outcome measure.

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.

Time frame: From Day 1 to Day 7 after study vaccination

Population: Safety population included all participants who received the study intervention and where appropriate informed consent was obtained. Here, Overall Number of Participants Analyzed signifies participants evaluable for 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. Results excluded local reactions and systemic events data.

Time frame: From study vaccination through 1 month after study vaccination

Population: Safety population included all participants who received the study intervention and where appropriate informed consent was obtained.

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.

Time frame: From study vaccination through 6 months after study vaccination

Population: Safety population included all participants who received the study intervention and where appropriate informed consent was obtained.

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.

Time frame: 1 month after study vaccination

Population: EIP included all assigned/ randomized participants who received study intervention to which they were randomized/assigned, had at least 1 valid and determinate immunogenicity result from blood sample collected within 28-42 days post the vaccination and had no other important protocol deviations. Analysis was performed in participants with or without evidence of infection up to 1 month post study vaccination.

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.

Time frame: 1 month after study vaccination

Population: EIP: all eligible, randomized participants who received study intervention to which they were randomized, had at least 1 valid and determinate immunogenicity result from blood sample collected within 28-42 days post study vaccination and had no other important protocol deviations. Analysis was performed in participants with or without evidence of infection up to 1 month post study vaccination. Overall Number of Participants Analyzed signifies participants evaluable for this outcome measure.

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).

Time frame: 1 month after study vaccination

Population: EIP: all eligible, randomized participants who received study intervention to which they were randomized, had at least 1 valid and determinate immunogenicity result from blood sample collected within 28-42 days post study vaccination and had no important protocol deviations. Analysis was performed in participants with or without evidence of infection up to 1 month post study vaccination. Here, Overall Number of Participants Analyzed signifies participants evaluable for this outcome measure.

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).

Time frame: 1 month after study vaccination

Population: EIP: all assigned/ randomized participants who received study intervention to which they were randomized/assigned, had at least 1 valid, determinate immunogenicity result from blood sample collected within 28-42 days post vaccination and had no other important protocol deviations. Analysis was performed in participants with or without evidence of infection up to 1 month post vaccination. Here, Overall Number of Participants Analyzed signifies participants evaluable for this outcome measure.

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).

Time frame: 1 month after study vaccination

Population: EIP: all eligible, randomized participants who received study intervention to which they were randomized, had at least 1 valid and determinate immunogenicity result from blood sample collected within 28-42 days post study vaccination and had no other important protocol deviations. Analysis was performed in participants with or without prior evidence of infection up to 1 month post vaccination. Overall Number of Participants Analyzed signifies participants evaluable for 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. GMFR from before the study vaccination to 1 month after study vaccination for Omicron BA.4/BA.5 and reference strain neutralizing titer was reported in this outcome measure. This outcome measure was planned per protocol to be analyzed in participants from Cohort 2 (Group 2) + Cohort 3 (Group 1), 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.

Time frame: From before the study vaccination to 1 month after study vaccination

Population: EIP included all assigned/ randomized participants who received study intervention to which they were randomized/assigned, had at least 1 valid and determinate immunogenicity result from blood sample collected within 28-42 days post the vaccination and had no other important protocol deviations. Analysis was performed in participants with or without evidence of infection up to 1 month post study vaccination. Here, ''Number Analyzed'' signifies participants evaluable for specified rows.

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 (Group 2) + Cohort 3 (Group 1), 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.

Time frame: At baseline and 1 month after study vaccination

Population: EIP included all assigned/ randomized participants who received study intervention to which they were randomized/assigned, had at least 1 valid and determinate immunogenicity result from blood sample collected within 28-42 days post the vaccination and had no other important protocol deviations. Analysis was performed in participants with or without evidence of infection up to 1 month post study vaccination. Here, ''Number Analyzed'' signifies participants evaluable for specified rows.

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 and BNT162b2 30 mcg in Study C4591031 \[NCT04955626\] Substudy E among participants \>55 years of age are presented as descriptive data. This outcome measure was planned per protocol to be analyzed in participants from Cohort 2 (Group 2) + Cohort 3 (Group 1), 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.

Time frame: 1 month after the study vaccination

Population: EIP was analyzed. Analysis was performed in EIP with or without evidence of infection up to 1 month post study vaccination. Here, Overall Number of Participants Analyzed signifies participants evaluable for this outcome measure and ''Number Analyzed'' signifies participants evaluable for specified rows.

Model based GMT of reference strain NTs induced by BNT162b2 Bivalent 30mcg groups of study C4591044 \[NCT05472038\] Cohort 2/3 combined and BNT162b2 30 mcg of study C4591031 \[NCT04955626\] Substudy E among participants \>55 years of age presented as descriptive data. GMTs, 2-sided 95% CIs calculated by exponentiating LS means, corresponding CIs based on analysis of logarithmically transformed NT using linear regression model with terms of baseline NT (log scale), vaccine group. Assay results below LLOQ set to 0.5\*LLOQ. Model based GMR: OMI BA.4/BA.5 NTs induced 1 month after BNT162b2 Bivalent vaccination in study C4591044 to 1 month after BNT162b2 vaccination in study C4591031 \[NCT04955626\] among participants \>55 years of age 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.

Time frame: 1 month after study vaccination

Population: EIP included all assigned/ randomized participants who received study intervention to which they were randomized/assigned, had at least 1 valid and determinate immunogenicity result from blood sample collected within 28-42 days post the vaccination and had no other important protocol deviations. Analysis in participants with or without prior evidence of infection up to 1 month post vaccination. Overall Number of Participants Analyzed signifies participants evaluable for this outcome measure.