A Study to Evaluate the Safety, Tolerability, and Immunogenicity of a Combined Modified RNA Vaccine Candidate Against COVID-19 and Influenza.

Study at a glance

From the registry record, last updated by the sponsor on 4 Dec 2025. Recruitment status is as the sponsor reported it: confirm with the study team.

Official title

A PHASE 3, RANDOMIZED, OBSERVER-BLINDED STUDY TO EVALUATE THE SAFETY, TOLERABILITY, AND IMMUNOGENICITY OF A COMBINED MODIFIED RNA VACCINE CANDIDATE AGAINST COVID-19 AND INFLUENZA IN HEALTHY INDIVIDUALS

ClinicalTrials.gov ID

NCT06178991

Acronym / sponsor ID

C5261002

Conditions

Influenza, COVID-19

Phase

Phase 3

Study type

Interventional

Recruitment status

Completed

Enrolment

8,795 participants (actual)

Lead sponsor

BioNTech SEIndustry (pharma, biotech, devices)

Collaborators

Pfizer

Study start

20 Dec 2023 (actual)

Primary completion

26 Nov 2024 (actual)

Study completion

26 Nov 2024 (actual)

First posted

21 Dec 2023 (actual)

Results

Posted 4 Dec 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

Double blind (participant, investigator)

Number of arms

8

Who may qualify

Ages

18 to 64 years

Sex

All

Healthy volunteers

Accepted

Age groups

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 With Any Local Reactions for up to 7 Days Following Vaccination in Investigational Vaccine Extremity

   Time frame: From Day 1 through Day 7 after Vaccination [Vaccination on Day 1]

   Local reactions included redness, swelling, and pain at the injection site, were recorded in the electronic dairy (e-diary) or case report form (CRF) after vaccination. Local reactions were graded per the 'Local Reaction Grading Scale' per protocol. Percentage of participants with at least 1 local reaction of grade 1 and above were reported in this outcome measure.

2. Cohort 2: Percentage of Participants With Any Local Reactions for up to 7 Days Following Vaccination in Investigational Vaccine Extremity

   Time frame: From Day 1 through Day 7 after Vaccination [Vaccination on Day1]

   Local reactions included redness, swelling, and pain at the injection site, were recorded in the e-diary or CRF after vaccination. Local reactions were graded per the 'Local Reaction Grading Scale' per protocol. Percentage of participants with at least 1 local reaction of grade 1 and above were reported in this outcome measure.

3. Cohort 3: Percentage of Participants With Any Local Reactions for up to 7 Days Following Vaccination in Investigational Vaccine Extremity

   Time frame: From Day 1 through Day 7 after Vaccination [Vaccination on Day 1]

   Local reactions included redness, swelling, and pain at the injection site, were recorded in the e-diary or CRF after vaccination. Local reactions were graded per the 'Local Reaction Grading Scale' per protocol. Percentage of participants with at least 1 local reaction of grade 1 and above were reported in this outcome measure.

4. Cohort 1: Percentage of Participants With Any Systemic Events for up to 7 Days Following Vaccination

   Time frame: From Day 1 through Day 7 after Vaccination [Vaccination on Day 1]

   Systemic events including fever, vomiting, diarrhea, headache, fatigue, chills, new or worsened muscle pain and new or worsened joint pain were recorded in an e-diary or CRF after vaccination. Systemic events were graded per the 'Systemic Events Grading Scale' per protocol. Percentage of participants with at least 1 systemic event of grade 1 and above were reported in this outcome measure.

5. Cohort 2: Percentage of Participants With Any Systemic Events for up to 7 Days Following Vaccination

   Time frame: From Day 1 through Day 7 after Vaccination [Vaccination on Day 1]

   Systemic events including fever, vomiting, diarrhea, headache, fatigue, chills, new or worsened muscle pain and new or worsened joint pain were recorded in an e-diary or CRF after vaccination. Systemic events were graded per the 'Systemic Events Grading Scale' per protocol. Percentage of participants with at least 1 systemic event of grade 1 and above were reported in this outcome measure.

6. Cohort 3: Percentage of Participants With Any Systemic Events for up to 7 Days Following Vaccination

   Time frame: From Day 1 through Day 7 after Vaccination [Vaccination on Day 1]

   Systemic events including fever, vomiting, diarrhea, headache, fatigue, chills, new or worsened muscle pain and new or worsened joint pain were recorded in an e-diary or CRF after vaccination. Systemic events were graded per the 'Systemic Events Grading Scale' per protocol. Percentage of participants with at least 1 systemic event of grade 1 and above were reported in this outcome measure.

7. Cohort 1: Percentage of Participants Reporting Adverse Events (AEs) From Vaccination Through 4 Weeks After Vaccination

   Time frame: From Vaccination on Day 1 through 4 Weeks after Vaccination

   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. AEs included both serious and all non-serious AEs. Serious AE (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, any other pre-specified criteria in protocol of the study or other important medical event. Only AEs collected by non-systematic assessment (excluding local reactions and systematic events) were included in this outcome measure.

8. Cohort 2: Percentage of Participants Reporting AEs From Vaccination Through 4 Weeks After Vaccination

   Time frame: From Vaccination on Day 1 through 4 Weeks after Vaccination

   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. AEs included both serious and all non-serious AEs. 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, any other pre-specified criteria in protocol of the study or other important medical event. Only AEs collected by non-systematic assessment (excluding local reactions and systematic events) were included in this outcome measure.

9. Cohort 3: Percentage of Participants Reporting AEs From Vaccination Through 4 Weeks After Vaccination

   Time frame: From Vaccination on Day 1 through 4 Weeks after Vaccination

   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. AEs included both serious and all non-serious AEs. 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, any other pre-specified criteria in protocol of the study or other important medical event. Only AEs collected by non-systematic assessment (excluding local reactions and systematic events) were included in this outcome measure.

10. Cohort 1: Percentage of Participants Reporting SAEs From Vaccination Through 6 Months After Vaccination

    Time frame: From Vaccination on Day 1 through 6 Months after Vaccination

    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 any other pre-specified criteria in protocol of the study or other important medical event.

11. Cohort 2: Percentage of Participants Reporting SAEs From Vaccination Through 6 Months After Vaccination

    Time frame: From Vaccination on Day 1 through 6 Months after Vaccination

    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 any other pre-specified criteria in protocol of the study or other important medical event.

12. Cohort 3: Percentage of Participants Reporting SAEs From Vaccination Through 6 Months After Vaccination

    Time frame: From Vaccination on Day 1 through 6 Months after Vaccination

    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 any other pre-specified criteria in protocol of the study or other important medical event.

13. Cohort 2: Geometric Mean Titer (GMT) and Geometric Mean Ratio (GMR) of Strain-Specific Hemagglutination Inhibition Assay (HAI) Titers at 4 Weeks After Vaccination: Non-inferiority

    Time frame: At 4 Weeks after Vaccination

    GMTs and the corresponding 2-sided confidence interval (CIs) were calculated by exponentiating the mean logarithm of the titers and the corresponding CIs (based on the Student t distribution). Assay results below the lower limit of quantitation (LLOQ) were set to 0.5 *LLOQ. GMTs were reported in the descriptive data section of this outcome measure. GMRs were reported in the statistical analysis section. Data was reported for the following strains: H1N1, H3N2 and Victoria.

14. Cohort 2: Percentage of Participants and Difference in Percentage of Participants With Strain-Specific HAI Seroconversion at 4 Weeks After Vaccination: Non-inferiority

    Time frame: At 4 Weeks after Vaccination

    Seroconversion was defined as having an HAI titer <1:10 prior to vaccination and greater than or equal to (>=) 1:40 at the postvaccination time point of interest, or an HAI titer of >=1:10 prior to vaccination with a minimum 4-fold rise at the postvaccination time point of interest. Percentage of participants with seroconversion were reported in the descriptive data section of this outcome measure. Difference in percentage of participants with seroconversion were reported in the statistical analysis section. Data was reported for the following strains: H1N1, H3N2 and Victoria.

15. Cohort 2: GMT and GMR of Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV-2) Neutralizing Titers at 4 Weeks After Vaccination: Non-inferiority

    Time frame: At 4 Weeks after Vaccination

    GMTs and the corresponding 2-sided CIs were calculated by exponentiating the mean logarithm of the titers and the corresponding CIs (based on the Student t distribution). Assay results below the LLOQ were set to 0.5 *LLOQ. GMTs were reported in the descriptive data section of this outcome measure. GMRs were reported in the statistical analysis section.

16. Cohort 2: Percentage of Participants and Difference in Percentage of Participants With SARS-CoV-2 Seroresponse at 4 Weeks After Vaccination: Non-inferiority

    Time frame: At 4 Weeks after Vaccination

    Seroresponse was defined as achieving a postvaccination >=4-fold rise from baseline (before the study vaccination). If the baseline measurement was below the LLOQ, the postvaccination measure of >=4*LLOQ was considered seroresponse. Percentage of participants with seroresponse were reported in the descriptive data section of this outcome measure. Difference in percentage of participants with seroresponse were reported in the statistical analysis section.

Results and safety

Loading the posted results from ClinicalTrials.gov…

Research links

• Official record on ClinicalTrials.govLast updated by the sponsor 4 Dec 2025.
• Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
• Derived from this study: PubMed 42646694Puebla YP, Nicholls H, Fitz-Patrick D, Horton LE, Gawel MW, Martinez RD, Wang X, Keep G, Xu X, Gomme E, Scully I, Allen PS, Swanson KA, Salisch N, Mensa FJ, Rizzi R, Tureci O, Sahin U, Anderson AS, Gurtman A, Lindert KA. Phase 3 Randomized Study Investigating the Safety, Tolerability, and Immunogenicity of a Combination Modified Messenger RNA Vaccine Against Influenza and COVID-19 in Healthy Adults. Vaccines (Basel). 2026 Aug 5;14(8):677. doi: 10.3390/vaccines14080677.
• 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.

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