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

Study at a glance

From the registry record, last updated by the sponsor on 1 Oct 2025. Recruitment status is as the sponsor reported it: confirm with the study team.

Official title

AN INTERVENTIONAL, RANDOMIZED, ACTIVE-CONTROLLED, PHASE 1/2/3 STUDY TO INVESTIGATE THE SAFETY, TOLERABILITY, AND IMMUNOGENICITY OF BNT162b RNA-BASED VACCINE CANDIDATES IN COVID-19 VACCINE-EXPERIENCED HEALTHY INDIVIDUALS

ClinicalTrials.gov ID

NCT05472038

Acronym / sponsor ID

C4591044

Conditions

SARS-CoV-2 Infection, COVID-19

Keywords

SARS-CoV-2 infection, COVID-19

Phase

Phase 2/3

Study type

Interventional

Recruitment status

Completed

Enrolment

1,453 participants (actual)

Lead sponsor

BioNTech SEIndustry (pharma, biotech, devices)

Collaborators

Pfizer

Study start

26 Jul 2022 (actual)

Primary completion

26 Mar 2024 (actual)

Study completion

26 Mar 2024 (actual)

First posted

25 Jul 2022 (actual)

Results

Posted 1 Oct 2025

Clinical summary

The research question as the sponsor registered it. This describes what the study plans to test, not what it found.

Study design

Primary purpose

Prevention

Allocation

Randomised

Intervention model

Parallel groups

Masking

Quadruple blind (participant, care provider, investigator, outcomes assessor)

Number of arms

14

Model description

Phase 1/2/3, randomized, active-controlled, parallel group study.

Who may qualify

Ages

12 years and older

Sex

All

Healthy volunteers

Accepted

Age groups

Child, Adult, Older adult

Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.

Interventions

Primary outcome

1. Cohort 1: Percentage of Participants Reporting Local Reactions Within 7 Days After Study Vaccination

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

   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.

2. Cohort 1: Percentage of Participants Reporting Systemic Events Within 7 Days After Study Vaccination

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

   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.

3. Cohort 1: Percentage of Participants With Adverse Events (AEs) From Study Vaccination Through 1 Month After Study Vaccination

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

   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.

4. Cohort 1: Percentage of Participants With Serious Adverse Events (SAEs) From Study Vaccination Through 6 Months After Study Vaccination

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

   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.

5. Cohort 1: Geometric Mean Titer (GMT) of SARS-CoV-2 Omicron Strain (BA.1 and BA.2) and Reference Strain Neutralizing Titers (NTs) at Baseline- Participants Without Evidence of Infection

   Time frame: At baseline (before study vaccination)

   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.

6. Cohort 1: GMT of SARS-CoV-2 Omicron Strain (BA.1 and BA.2) and Reference Strain NTs at Baseline- Participants With or Without Evidence of Infection

   Time frame: At baseline (before 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).

7. Cohort 1: GMT of SARS-CoV-2 Omicron Strain (BA.1 and BA.2) and Reference Strain NTs at 1 Month After Study Vaccination- Participants Without Evidence of Infection

   Time frame: 1 month after the 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). Assay results below the LLOQ were set to 0.5*LLOQ.

8. Cohort 1: GMT of SARS-CoV-2 Omicron Strain (BA.1 and BA.2) and Reference Strain NTs at 1 Month After Study Vaccination- Participants With or Without Evidence of Infection

   Time frame: 1 month after the 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). Assay results below the LLOQ were set to 0.5*LLOQ.

9. Cohort 1: Geometric Mean Fold Rise (GMFR) of SARS-CoV-2 Omicron Strain (BA.1 and BA.2) and Reference Strain- NTs From Before the Study Vaccination to 1 Month After the Study Vaccination- Participants Without Evidence of Infection

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

   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.

10. Cohort 1: GMFR of SARS-CoV-2 Omicron Strain (BA.1 and BA2) and Reference Strain- NTs From Before the Study Vaccination to 1 Month After the Study Vaccination- Participants With or Without Evidence of Infection

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

    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.

11. Cohort 1: Percentage of Participants With Seroresponse to SARS-CoV-2 Omicron Strain (BA.1 and BA.2) and Reference Strain- NTs at 1 Month After Study Vaccination- Participants Without Evidence of Infection

    Time frame: 1 month after the study vaccination

    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.

12. Cohort 1: Percentage of Participants With Seroresponse to SARS-CoV-2 Omicron Strain (BA.1 and BA.2) and Reference Strain- NTs at 1 Month After Study Vaccination- Participants With or Without Evidence of Infection

    Time frame: 1 month after the study vaccination

    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.

13. Cohort 2: Percentage of Participants Reporting Local Reactions Within 7 Days After Study Vaccination

    Time frame: From Day 1 to Day 7 after 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.

14. Cohort 2: Percentage of Participants Reporting Systemic Events Within 7 Days After Study Vaccination

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

    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.

15. Cohort 2: Percentage of Participants With AEs From Study Vaccination Through 1 Month After Study Vaccination

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

    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.

16. Cohort 2: Percentage of Participants With SAEs From Study Vaccination Through 6 Month After Study Vaccination

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

    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.

17. Cohort 2 (Group 2 and 4) + Cohort 3 (Group 1 and Group 2): Percentage of Participants Reporting Local Reactions Within 7 Days After Study Vaccination

    Time frame: From Day 1 to Day 7 after 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.

18. Cohort 2 (Group 2 and 4) + Cohort 3 (Group 1 and Group 2): Percentage of Participants Reporting Systemic Events Within 7 Days After Study Vaccination

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

    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.

19. Cohort 2 (Group 2 and 4) + Cohort 3 (Group 1 and Group 2): Percentage of Participants With AEs From Study Vaccination Through 1 Month After Study Vaccination

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

    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.

20. Cohort 2 (Group 2 and 4) + Cohort 3 (Group 1 and Group 2): Percentage of Participants With SAEs From Study Vaccination Through 6 Month After Study Vaccination

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

    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.

21. GMR of Omicron (BA.4/BA.5)- NT of BNT162b2 Bivalent [WT/ OMI BA.4/ BA.5] 30 mcg Cohort 2 (Group 4)/ Cohort 3 (Group 2) Combined in C4591044 Compared to NT of BNT162b2 30 mcg in C4591031 [NCT04955626]- 1 Month After Vaccination Among Participants >55 Years

    Time frame: 1 month after study vaccination

    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).

22. Difference in Percentage of Participants With Seroresponse to OMI BA.4/BA.5 for BNT162b2 Bivalent[WT/OMI BA.4/BA.5]30mcg Cohort2(Group4)/Cohort3(Group2)Combined in C4591044 and BNT162b2 30mcg in C4591031-1 Month After Vaccination in Participants >55 Years

    Time frame: 1 month after 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.

23. GMR of Omicron (BA.4/BA.5)- NTs of BNT162b2 Bivalent[WT/OMI BA.4/BA.5]30mcg Cohort2 (Group2)/Cohort3 (Group1)Combined for 18-55 Years Compared to BNT162b2 30mcg Cohort2 (Group4)/Cohort3 (Group2)Combined for >55 Years- 1 Month After Vaccination in C4591044

    Time frame: 1 month after study vaccination

    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).

24. Difference in Percentage of Participants With Seroresponse to OMI BA.4/BA.5 of BNT162b2 Bivalent [WT/OMI BA.4/BA.5] 30 mcg Cohort2 (Group2)/Cohort3 (Group1) 18-55 Years and Cohort2 (Group4)/Cohort3 (Group2) >55 Years- 1 Month After Vaccination in C4591044

    Time frame: 1 month after study vaccination

    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).

25. Cohort 2: GMT of SARS-CoV-2 Omicron Strain (BA.1 and BA.4/BA.5) and Reference Strain NTs at Baseline- Participants With or Without Evidence of Infection

    Time frame: At baseline (before 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). 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.

26. Cohort 2: GMT of SARS-CoV-2 Omicron Strain (BA.1 and BA.4/BA.5) and Reference Strain NTs at 1 Month- Participants With or Without Evidence of Infection

    Time frame: 1 month after the 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). 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.

27. Cohort 2: GMFR of SARS-CoV-2 Omicron Strain (BA.1 and BA.4/BA.5) and Reference Strain- NTs From Before the Study Vaccination to 1 Month After the Study Vaccination- Participants With or Without Evidence of Infection

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

    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.

28. Cohort 2: Percentage of Participants With Seroresponse to SARS-CoV-2 Omicron Strain (BA.1 and BA.4/BA.5) and Reference Strain- NTs at 1 Month After Study Vaccination- Participants With or Without Evidence of Infection

    Time frame: 1 month after the study vaccination

    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.

29. Cohort 4: Percentage of Participants Reporting Local Reactions Within 7 Days After Study Vaccination

    Time frame: From Day 1 to Day 7 after 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.

30. Cohort 4: Percentage of Participants Reporting Systemic Events Within 7 Days After Study Vaccination

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

    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.

31. Cohort 4: Percentage of Participants With AEs From Study Vaccination Through 1 Month After Study Vaccination

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

    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.

32. Cohort 4: Percentage of Participants With SAEs From Study Vaccination Through 6 Months After Study Vaccination

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

    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.

33. Cohort 4: GMT of SARS-CoV-2 Omicron Strain (BA.4/BA.5) and Reference Strain NTs at Baseline- Participants With or Without Evidence of Infection

    Time frame: At baseline (before 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).

34. Cohort 4: GMT of SARS-CoV-2 Omicron Strain (BA.4/BA.5) and Reference Strain NTs at 1 Month After Study Vaccination- Participants With or Without Evidence of Infection

    Time frame: 1 month after the 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).

35. Cohort 4: GMFR of SARS-CoV-2 Omicron Strain (BA.4/BA.5) and Reference Strain- NTs From Before the Study Vaccination to 1 Month After the Study Vaccination- Participants With or Without Evidence of Infection

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

    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.

36. Cohort 4: Percentage of Participants With Seroresponse to SARS-CoV-2 Omicron Strain (BA.4/BA.5) and Reference Strain- NTs at 1 Month After Study Vaccination- Participants With or Without Evidence of Infection

    Time frame: 1 month after study vaccination

    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.

Results and safety

Loading the posted results from ClinicalTrials.gov…

Research links

• Official record on ClinicalTrials.govLast updated by the sponsor 1 Oct 2025.
• Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
• Derived from this study: PubMed 39066372Gayed J, Bangad V, Xu X, Mensa F, Cutler M, Tureci O, Sahin U, Modjarrad K, Swanson KA, Anderson AS, Gurtman A, Kitchin N; C4591054 Study Group. Immunogenicity of the Monovalent Omicron XBB.1.5-Adapted BNT162b2 COVID-19 Vaccine against XBB.1.5, BA.2.86, and JN.1 Sublineages: A Phase 2/3 Trial. Vaccines (Basel). 2024 Jul 2;12(7):734. doi: 10.3390/vaccines12070734.
• Derived from this study: PubMed 38400102Gayed J, Diya O, Lowry FS, Xu X, Bangad V, Mensa F, Zou J, Xie X, Hu Y, Lu C, Cutler M, Belanger T, Cooper D, Koury K, Anderson AS, Tureci O, Sahin U, Swanson KA, Modjarrad K, Gurtman A, Kitchin N; C4591054 Study Group. Safety and Immunogenicity of the Monovalent Omicron XBB.1.5-Adapted BNT162b2 COVID-19 Vaccine in Individuals >/=12 Years Old: A Phase 2/3 Trial. Vaccines (Basel). 2024 Jan 24;12(2):118. doi: 10.3390/vaccines12020118.
• Derived from this study: PubMed 38016021Usdan L, Patel S, Rodriguez H, Xu X, Lee DY, Finn D, Wyper H, Lowry FS, Mensa FJ, Lu C, Cooper D, Koury K, Anderson AS, Tureci O, Sahin U, Swanson KA, Gruber WC, Kitchin N; C4591044 Study Group. A Bivalent Omicron-BA.4/BA.5-Adapted BNT162b2 Booster in >/=12-Year-Olds. Clin Infect Dis. 2024 May 15;78(5):1194-1203. doi: 10.1093/cid/ciad718.
• To obtain contact information for a study center near you, click here.Link provided by the sponsor.
• Individual participant dataSharing planned: No

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Referral and contact

AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.

31 sites in 1 country: see every site and its status.