A Study to Evaluate the Safety, Tolerability, and Immunogenicity of a Modified RNA Vaccine Against Influenza

Study at a glance

From the registry record, last updated by the sponsor on 12 Mar 2024. Recruitment status is as the sponsor reported it: confirm with the study team.

Official title

A PHASE 1/2 RANDOMIZED STUDY TO EVALUATE THE SAFETY, TOLERABILITY, AND IMMUNOGENICITY OF A MODIFIED RNA VACCINE AGAINST INFLUENZA IN HEALTHY INDIVIDUALS

ClinicalTrials.gov ID

NCT05052697

Acronym / sponsor ID

C4781001

Conditions

Influenza, Human

Keywords

Grippe, Flu, Influenza, Vaccine, RNA vaccine

Phase

Phase 1/2

Study type

Interventional

Recruitment status

Completed

Enrolment

1,158 participants (actual)

Lead sponsor

PfizerIndustry (pharma, biotech, devices)

Study start

13 Sep 2021 (actual)

Primary completion

27 Jan 2023 (actual)

Study completion

27 Jan 2023 (actual)

First posted

22 Sep 2021 (actual)

Results

Posted 12 Mar 2024

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

28

Who may qualify

Ages

18 to 85 years

Sex

All

Healthy volunteers

Accepted

Age groups

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. Percentage of Participants Reporting Local Reactions After Vaccination 1: Substudy A

   Time frame: From Day 1 to Day 7 after Vaccination 1

   Local reactions included pain at the injection site, redness and swelling and were recorded by participants in an electronic diary. 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 (Grade 1): greater than (>) 2.0 cm to 5.0 cm; moderate (Grade 2): >5.0 cm to 10.0 cm; severe (Grade 3): >10 cm; potentially life-threatening (Grade 4): necrosis or exfoliative dermatitis (redness) and necrosis (swelling). Pain at injection site was graded as mild (Grade 1): did not interfere with activity; moderate (Grade 2): interfered with activity; severe (Grade 3): prevented daily activity and potentially life-threatening (Grade 4): emergency room visit or hospitalization for severe pain. Grade 4 reactions were classified by the investigator or medically qualified person. Exact 2-sided confidence interval was based on the Clopper and Pearson method.

2. Percentage of Participants Reporting Local Reactions After Vaccination 2: Substudy A

   Time frame: From Day 1 to Day 7 after Vaccination 2

   Local reactions included pain at the injection site, redness and swelling and were recorded by participants in an electronic diary. 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 (Grade 1): >2.0 cm to 5.0 cm; moderate (Grade 2): >5.0 cm to 10.0 cm; severe (Grade 3): >10 cm; potentially life-threatening (Grade 4): necrosis or exfoliative dermatitis. Pain at injection site was graded as mild (Grade 1): did not interfere with activity; moderate (Grade 2): interfered with activity; severe (Grade 3): prevented daily activity and potentially life-threatening (Grade 4): emergency room visit or hospitalization for severe pain. Grade 4 reactions were classified by the investigator or medically qualified person. Exact 2-sided confidence interval was based on the Clopper and Pearson method.

3. Percentage of Participants Reporting Systemic Events After Vaccination 1: Substudy A

   Time frame: From Day 1 to Day 7 After Vaccination 1

   Systemic events included fever, vomiting, diarrhea, headache,fatigue,chills,new/worsened muscle pain \& new/worsened joint pain \& recorded by participants in an electronic diary.Fever defined as oral temperature greater than equal to(>=)38.0 degrees Celsius(deg C) \& categorized as>=38.0 to 38.4 deg C, >38.4 to 38.9 deg C,>38.9 to 40.0 deg C \& >40.0 deg C. Vomiting graded as:Grade(G)1:1-2 times in 24 hours(h);G2:>2 times in 24h;G3:required Intravenous (IV) hydration.Diarrhea graded as: G1:2-3 loose stools in 24h;G2: 4-5 loose stools in 24h;G3: 6 or more loose stools in 24h.Headache,fatigue,chills, new/worsened muscle pain \& new/worsened joint pain:G1:didn't interfere with activity;G2: some interference with activity;G3:prevented daily routine activity.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.Exact 2-sided confidence interval based on Clopper and Pearson method.

4. Percentage of Participants Reporting Systemic Events After Vaccination 2: Substudy A

   Time frame: From Day 1 to Day 7 after Vaccination 2

   Systemic events included fever, vomiting, diarrhea, headache, fatigue, chills, new/worsened muscle pain \& new /worsened joint pain \& recorded by participants in electronic diary. Fever defined as oral temperature >=38.0 deg C \& categorized as >=38.0 to 38.4 deg C, >38.4 to 38.9 deg C, >38.9 to 40.0 deg C \& >40.0 deg C. Vomiting graded as: Grade(G) 1: 1-2 times in 24 h; G2: >2 times in 24 h; G3: required IV hydration. Diarrhea graded as: G1: 2-3 loose stools in 24 h; G2: 4-5 loose stools in 24 h; G3: 6 or more loose stools in 24 h. Headache, fatigue, chills, new/worsened muscle pain \& new/worsened joint pain: G1: didn't interfere with activity; G2: some interference with activity; G3: prevented daily routine activity. 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. Exact 2-sided confidence interval based on Clopper and Pearson method.

5. Percentage of Participants Reporting Adverse Events After Vaccination 1: Substudy A

   Time frame: From Day 1 up to 4 weeks After Vaccination 1

   An adverse event (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 systematic events) were reported in this outcome measure.

6. Percentage of Participants Reporting Adverse Events After Vaccination 2: Substudy A

   Time frame: From Day 1 up to 4 weeks After vaccination 2

   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 reported in this outcome measure.

7. Percentage of Participants Reporting Serious Adverse Events (SAE) From First Vaccination to 6 Months After Last Vaccination: Substudy A

   Time frame: From vaccination 1 on day 1 up to 6 months after vaccination 2

   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.

8. Percentage of Participants With Abnormal Hematology Values at 2 Days After Vaccination 1: Substudy A

   Time frame: 2 days after vaccination 1

   Hematology parameters included erythrocytes, lymphocytes, neutrophils, eosinophils/leukocytes, erythrocyte (ery) mean corpuscular volume, ery. mean corpuscular hemoglobin and ery. mean corpuscular hemoglobin concentration. The primary criteria were as follows erythrocytes, lymphocytes, neutrophils: <0.8*lower limit of normal (LLN); Lymphocytes/Leukocytes, Eosinophils/Leukocytes, Monocytes/Leukocytes: >1.2*upper limit of normal (ULN); Ery. Mean Corpuscular Volume:>1.1*ULN; Ery. Mean Corpuscular Hemoglobin and Ery.Mean Corpuscular hemoglobin Concentration: < 0.9*LLN. Also add 95% CI was based on Clopper and Pearson method.

9. Percentage of Participants With Abnormal Hematology Values at 1 Week After Vaccination 1: Substudy A

   Time frame: 1 week after vaccination 1

   Hematology parameters included erythrocytes, neutrophils, eosinophils/leukocytes, monocytes/leukocytes, ery mean corpuscular hemoglobin. The primary criteria were as follows erythrocytes and neutrophils: <0.8* LLN; Eosinophils/Leukocytes and Monocytes/Leukocytes: >1.2* ULN; Ery. Mean Corpuscular Hemoglobin:>1.1*ULN. 95% CI was based on Clopper and Pearson method.

10. Percentage of Participants With Abnormal Chemistry Values at 2 Days After Vaccination 1: Substudy A

    Time frame: 2 days after vaccination 1

    Chemistry parameters included blood urea nitrogen and C-reactive protein. The primary criteria were as follows Blood Urea Nitrogen: > 1.3*ULN; C Reactive Protein: > 1.1*ULN. 95% CI was based on Clopper and Pearson method.

11. Percentage of Participants With Abnormal Chemistry Values at 1 Week After Vaccination 1: Substudy A

    Time frame: 1 week after vaccination 1

    Chemistry parameters included blood urea nitrogen and C-reactive protein. The primary criteria were as follows Blood Urea Nitrogen: > 1.3*ULN; C Reactive Protein: > 1.1*ULN. Also add 95% CI was based on Clopper and Pearson method.

12. Percentage of Participants With Grade Shifts in Hematology Values at 2 Days After Vaccination 1: Substudy A

    Time frame: From Baseline (prior to vaccination 1) to 2 days after vaccination 1

    Hematology parameters included hemoglobin, lymphocytes, neutrophils decrease, platelets decrease, white blood cells (WBC) decrease and WBC increase. Laboratory abnormalities were graded by Food and Drug Administration (FDA) toxicity grading scale for healthy adult volunteers enrolled in preventive vaccine clinical trials as grade 1=mild; grade 2=moderate; grade 3=severe and grade 4=potentially life-threatening. Percentage of participants with shift in hematology values were reported in this outcome measure. Categories with at least 1 non-zero data values showing any shift in Grade from baseline to 2 days after vaccination 1 were reported. Participants whose grade category was unchanged (e.g. normal to normal) were not reported.

13. Percentage of Participants With Grade Shifts in Hematology Values at 1 Week After Vaccination 1: Substudy A

    Time frame: From Baseline (prior to vaccination 1) to 1 week after vaccination 1

    Hematology parameters included hemoglobin, lymphocytes, neutrophils decrease, WBC decrease and WBC increase. Laboratory abnormalities were graded by FDA toxicity grading scale for healthy adult volunteers enrolled in preventive vaccine clinical trials as grade 1=mild; grade 2=moderate; grade 3=severe and grade 4=potentially life-threatening. Percentage of participants with shift in hematology values were reported in this outcome measure. Categories with at least 1 non-zero data values showing any shift in Grade from baseline to 1 week after vaccination 1 were reported. Participants whose grade category was unchanged (e.g. normal to normal) were not reported.

14. Percentage of Participants With Grade Shifts in Chemistry Laboratory Values at 2 Days After Vaccination 1: Substudy A

    Time frame: From Baseline (prior to vaccination 1) to 2 days after vaccination 1

    Chemistry abnormalities were graded by toxicity grading scale for healthy adult volunteers enrolled in preventive vaccine clinical trials as grade 1=mild; grade 2=moderate; grade 3=severe and grade 4=potentially life-threatening. Percentage of participants with shift in chemistry values were reported in this outcome measure. Categories with at least 1 non-zero data values showing any shift in Grade from baseline to 2 days after vaccination 1 (post-baseline) were reported. Participants whose grade category was unchanged (e.g. normal to normal) were not reported. The parameters reported were - Alanine Aminotransferase Increased (ALP), Alkaline Phosphatase Increased (ALP), Aspartate Aminotransferase Increased (AST), Creatinine Increased and Urea Nitrogen.

15. Percentage of Participants With Grade Shifts in Chemistry Laboratory Values at 1 Week After Vaccination 1: Substudy A

    Time frame: From Baseline (prior to vaccination 1) to 1 week after vaccination 1

    Chemistry abnormalities were graded by toxicity grading scale for healthy adult volunteers enrolled in preventive vaccine clinical trials as grade 1=mild; grade 2=moderate; grade 3=severe and grade 4=potentially life-threatening. Percentage of participants with shift in chemistry values were reported in this outcome measure. Categories with at least 1 non-zero data values showing any shift in Grade from baseline to 1 week after vaccination 1 (post-baseline) were reported. Participants whose grade category was unchanged (e.g. normal to normal) were not reported. The parameters reported were - Alanine Aminotransferase Increased, Alkaline Phosphatase Increased, Aspartate Aminotransferase Increased, Creatinine Increased and Urea Nitrogen.

16. Percentage of Participants With New Electrocardiogram (ECG) Abnormalities at 2 Days After Vaccination 1: Substudy A

    Time frame: 2 days after vaccination 1

    An ECG abnormality was defined as any new abnormality that, as judged by a cardiologist, was consistent with probable or possible myocarditis or pericarditis, including: Sustained atrial or ventricular arrhythmias, Second-degree Mobitz Type II or worse atrioventricular block, new bundle branch block and Diffuse ST-segment elevation or PR-segment inversion, compatible with pericarditis.

17. Percentage of Participants With New Electrocardiogram (ECG) Abnormalities at 1 Week After Vaccination 1: Substudy A

    Time frame: 1 week after vaccination 1

    An ECG abnormality was defined as any new abnormality that, as judged by a cardiologist, was consistent with probable or possible myocarditis or pericarditis, including: Sustained atrial or ventricular arrhythmias, Second-degree Mobitz Type II or worse atrioventricular block, new bundle branch block and Diffuse ST-segment elevation or PR-segment inversion, compatible with pericarditis.

18. Percentage of Participants Reporting Local Reactions After Vaccination for 1-Visit Schedule (Initial Enrollment): Substudy B

    Time frame: From Day 1 to Day 7 after vaccination

    Local reactions included pain at the injection site, redness and swelling and were recorded by participants in an electronic diary. 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 (Grade 1): >2.0 cm to 5.0 cm; moderate (Grade 2): >5.0 cm to 10.0 cm; severe (Grade 3): >10 cm; potentially life-threatening (Grade 4): necrosis or exfoliative dermatitis. Pain at injection site was graded as mild (Grade 1): did not interfere with activity; moderate (Grade 2): interfered with activity; severe (Grade 3): prevented daily activity and potentially life-threatening (Grade 4): emergency room visit or hospitalization for severe pain. Exact 2-sided confidence interval was based on the Clopper and Pearson method.

19. Percentage of Participants Reporting Local Reactions After Vaccination 1 for 2- Visit Schedule (Initial Enrollment): Substudy B

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

    Local reactions included pain at the injection site, redness and swelling and were recorded by participants in an electronic diary. 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 (Grade 1): >2.0 cm to 5.0 cm; moderate (Grade 2): >5.0 cm to 10.0 cm; severe (Grade 3): >10 cm; potentially life-threatening (Grade 4): necrosis or exfoliative dermatitis. Pain at injection site was graded as mild (Grade 1): did not interfere with activity; moderate (Grade 2): interfered with activity; severe (Grade 3): prevented daily activity and potentially life-threatening (Grade 4): emergency room visit or hospitalization for severe pain. Exact 2-sided confidence interval was based on the Clopper and Pearson method.

20. Percentage of Participants Reporting Local Reactions After Vaccination 2 for 2- Visit Schedule (Initial Enrollment): Substudy B

    Time frame: From Day 1 to Day 7 after vaccination 2

    Local reactions included pain at the injection site, redness and swelling and were recorded by participants in an electronic diary. 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 (Grade 1): >2.0 cm to 5.0 cm; moderate (Grade 2): >5.0 cm to 10.0 cm; severe (Grade 3): >10 cm; potentially life-threatening (Grade 4): necrosis or exfoliative dermatitis. Pain at injection site was graded as mild (Grade 1): did not interfere with activity; moderate (Grade 2): interfered with activity; severe (Grade 3): prevented daily activity and potentially life-threatening (Grade 4): emergency room visit or hospitalization for severe pain. Exact 2-sided confidence interval was based on the Clopper and Pearson method.

21. Percentage of Participants Reporting Local Reactions After Vaccination for Expanded Enrollment: Substudy B

    Time frame: From Day 1 to Day 7 after vaccination 1 for all arms; From Day 1 to Day 7 after vaccination 2 for 2 doses of qIRV (dose level 1), 2-visit schedule arm

    Local reactions included pain at the injection site, redness and swelling and were recorded by participants in an electronic diary. 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 (Grade 1): >2.0 cm to 5.0 cm; moderate (Grade 2): >5.0 cm to 10.0 cm; severe (Grade 3): >10 cm; potentially life-threatening (Grade 4): necrosis or exfoliative dermatitis. Pain at injection site was graded as mild (Grade 1): did not interfere with activity; moderate (Grade 2): interfered with activity; severe (Grade 3): prevented daily activity and potentially life-threatening (Grade 4): emergency room visit or hospitalization for severe pain. Exact 2-sided confidence interval was based on the Clopper and Pearson method.

22. Percentage of Participants Reporting Systemic Events After Vaccination for 1-Visit Schedule (Initial Enrollment): Substudy B

    Time frame: From Day 1 to Day 7 after vaccination

    Systemic events included fever, vomiting, diarrhea, headache, fatigue, chills, new/worsened muscle pain \& new /worsened joint pain \& recorded by participants in electronic diary. Fever defined as oral temperature >=38.0 deg C \& categorized as >=38.0 to 38.4 deg C, >38.4 to 38.9 deg C, >38.9 to 40.0 deg C \& >40.0 deg C. Vomiting graded as: G 1: 1-2 times in 24 hrs; G 2: >2 times in 24 hrs; G 3: required IV hydration; G 4: emergency room visit/ hospitalization for hypotensive shock. Diarrhea graded as: G 1: 2-3 loose stools in 24 hrs; G 2: 4-5 loose stools in 24 hrs; G 3: 6 or more loose stools in 24 hrs \& G 4: emergency room visit/ hospitalization. Headache, fatigue, chills, new/worsened muscle pain \& new/worsened joint pain: G 1: didn't interfere with activity; G 2: some interference with activity; G 3: prevented daily routine activity \& G 4: emergency room visit/ hospitalization. Exact 2-sided confidence interval based on Clopper and Pearson method.

23. Percentage of Participants Reporting Systemic Events After Vaccination 1 for 2- Visit Schedule (Initial Enrollment): Substudy B

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

    Systemic events included fever, vomiting, diarrhea, headache, fatigue, chills, new/worsened muscle pain \& new /worsened joint pain \& recorded by participants in electronic diary. Fever defined as oral temperature >=38.0 deg C \& categorized as >=38.0 to 38.4 deg C, >38.4 to 38.9 deg C, >38.9 to 40.0 deg C \& >40.0 deg C. Vomiting graded as: G 1: 1-2 times in 24 hrs; G 2: >2 times in 24 hrs; G 3: required IV hydration; G 4: emergency room visit/ hospitalization for hypotensive shock. Diarrhea graded as: G 1: 2-3 loose stools in 24 hrs; G 2: 4-5 loose stools in 24 hrs; G 3: 6 or more loose stools in 24 hrs \& G 4: emergency room visit/ hospitalization. Headache, fatigue, chills, new/worsened muscle pain \& new/worsened joint pain: G 1: didn't interfere with activity; G 2: some interference with activity; G 3: prevented daily routine activity \& G 4: emergency room visit/ hospitalization. Exact 2-sided confidence interval based on Clopper and Pearson method.

24. Percentage of Participants Reporting Systemic Events After Vaccination 2 for 2-Visit Schedule (Initial Enrollment) : Substudy B

    Time frame: From day 1 to day 7 of vaccination 2

    Systemic events included fever, vomiting, diarrhea, headache, fatigue, chills, new/worsened muscle pain \& new /worsened joint pain \& recorded by participants in electronic diary. Fever defined as oral temperature >=38.0 deg C \& categorized as >=38.0 to 38.4 deg C, >38.4 to 38.9 deg C, >38.9 to 40.0 deg C \& >40.0 deg C. Vomiting graded as: G 1: 1-2 times in 24 hrs; G 2: >2 times in 24 hrs; G 3: required IV hydration; G 4: emergency room visit/ hospitalization for hypotensive shock. Diarrhea graded as: G: 1: 2-3 loose stools in 24 hrs; G 2: 4-5 loose stools in 24 hrs; G 3: 6 or more loose stools in 24 hrs \& G 4: emergency room visit/ hospitalization. Headache, fatigue, chills, new/worsened muscle pain \& new/worsened joint pain: G 1: didn't interfere with activity; G 2: some interference with activity; G 3: prevented daily routine activity \& G 4: emergency room visit/ hospitalization. Exact 2-sided confidence interval based on Clopper and Pearson method.

25. Percentage of Participants Reporting Systemic Events After Vaccination for Expanded Enrollment: Substudy B

    Time frame: From Day 1 to Day 7 after vaccination 1 for all arms; From Day 1 to Day 7 after vaccination 2 for 2 doses of qIRV (dose level 1), 2-visit schedule arm

    Systemic events included fever, vomiting, diarrhea, headache, fatigue, chills, new/worsened muscle pain \& new /worsened joint pain \& recorded by participants in electronic diary. Fever defined as oral temperature >=38.0 deg C \& categorized as >=38.0 to 38.4 deg C, >38.4 to 38.9 deg C, >38.9 to 40.0 deg C \& >40.0 deg C. Vomiting graded as: G 1: 1-2 times in 24 hrs; G 2: >2 times in 24 hrs; G 3: required IV hydration; G 4: emergency room visit/ hospitalization for hypotensive shock. Diarrhea graded as: G 1: 2-3 loose stools in 24 hrs; G 2: 4-5 loose stools in 24 hrs; G 3: 6 or more loose stools in 24 hrs \& G 4: emergency room visit/ hospitalization. Headache, fatigue, chills, new/worsened muscle pain \& new/worsened joint pain: G 1: didn't interfere with activity; G 2: some interference with activity; G 3: prevented daily routine activity \& G 4: emergency room visit/ hospitalization. Exact 2-sided confidence interval based on Clopper and Pearson method.

26. Percentage of Participants Reporting Adverse Events From First Vaccination Until 4 Weeks After Last Vaccination: Substudy B

    Time frame: From first vaccination to 4 weeks after last vaccination (i.e., Vaccination 1 for 1-visit schedule arms and Vaccination 2 for 2-visit schedule arms)

    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 systematic events) were reported in this outcome measure.

27. Percentage of Participants Reporting Serious Adverse Events From First Vaccination Until 6 Months After Last Vaccination: Substudy B

    Time frame: From first vaccination to 6 month after last vaccination (i.e., Vaccination 1 for 1-visit schedule arms and Vaccination 2 for 2-visit schedule arms)

    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.

28. Percentage of Participants Reporting Abnormal Troponin I Laboratory Values 2 Days After Vaccination 1 for 2-Visit Schedule (Initial Enrollment): Substudy B

    Time frame: 2 days after vaccination 1

    Percentage of participants reporting abnormal troponin I laboratory values 2 days after vaccination 1 were reported in this outcome measure.

29. Percentage of Participants Reporting Abnormal Troponin I Laboratory Values 2 Days After Vaccination 2 for 2-Visit Schedule (Initial Enrollment): Substudy B

    Time frame: 2 days after vaccination 2

    Percentage of participants reporting abnormal troponin I laboratory values 2 days after vaccination 2 were reported in this outcome measure.

30. Percentage of Participants Reporting Abnormal Troponin I Laboratory Values 2 Days After Vaccination for 1-Visit Schedule (Initial Enrollment): Substudy B

    Time frame: 2 days after vaccination

    Percentage of participants reporting abnormal troponin I laboratory values 2 days after vaccination were reported in this outcome measure.

31. Percentage of Participants Reporting Abnormal Troponin I Laboratory Values 2 Days After Vaccination for Expanded Enrollment: Substudy B

    Time frame: 2 days after last vaccination (i.e., Vaccination 1 for 1-visit schedule arms and Vaccination 2 for 2-visit schedule arms)

    Percentage of participants reporting abnormal troponin I laboratory values 2 days after vaccination were reported in this outcome measure.

32. Percentage of Participants Reporting New ECG Abnormalities 2 Days After Vaccination 1 for 2-Visit Schedule (Initial Enrollment): Substudy B

    Time frame: 2 days after vaccination 1

    Twelve lead ECGs were performed after the participant had rested quietly for at least 10 minutes in a supine position. An ECG abnormality was defined as any new abnormality that, as judged by a cardiologist, was consistent with probable or possible myocarditis or pericarditis, including: Sustained atrial or ventricular arrhythmias, Second-degree Mobitz Type II or worse atrioventricular block, new bundle branch block and Diffuse ST-segment elevation or PR-segment inversion, compatible with pericarditis.

33. Percentage of Participants Reporting New ECG Abnormalities 2 Days After Vaccination 2 for 2-Visit Schedule (Initial Enrollment): Substudy B

    Time frame: 2 days after vaccination 2

    Twelve lead ECGs were performed after the participant had rested quietly for at least 10 minutes in a supine position. An ECG abnormality was defined as any new abnormality that, as judged by a cardiologist, was consistent with probable or possible myocarditis or pericarditis, including: Sustained atrial or ventricular arrhythmias, Second-degree Mobitz Type II or worse atrioventricular block, new bundle branch block and Diffuse ST-segment elevation or PR-segment inversion, compatible with pericarditis.

34. Percentage of Participants Reporting New ECG Abnormalities 2 Days After Vaccination 1 for 1-Visit Schedule (Initial Enrollment): Substudy B

    Time frame: 2 days after vaccination 1

    Twelve lead ECGs were performed after the participant had rested quietly for at least 10 minutes in a supine position. An ECG abnormality was defined as any new abnormality that, as judged by a cardiologist, was consistent with probable or possible myocarditis or pericarditis, including: Sustained atrial or ventricular arrhythmias, Second-degree Mobitz Type II or worse atrioventricular block, new bundle branch block and Diffuse ST-segment elevation or PR-segment inversion, compatible with pericarditis.

35. Percentage of Participants Reporting New ECG Abnormalities 2 Days After Vaccination for Expanded Enrollment: Substudy B

    Time frame: 2 days after last vaccination (i.e., Vaccination 1 for 1-visit schedule arms and Vaccination 2 for 2-visit schedule arms)

    Twelve lead ECGs were performed after the participant had rested quietly for at least 10 minutes in a supine position. An ECG abnormality was defined as any new abnormality that, as judged by a cardiologist, was consistent with probable or possible myocarditis or pericarditis, including: Sustained atrial or ventricular arrhythmias, Second-degree Mobitz Type II or worse atrioventricular block, new bundle branch block and Diffuse ST-segment elevation or PR-segment inversion, compatible with pericarditis.

Results and safety

Loading the posted results from ClinicalTrials.gov…

Research links

• Official record on ClinicalTrials.govLast updated by the sponsor 12 Mar 2024.
• Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
• Derived from this study: PubMed 40333267Branche A, Mulligan MJ, Maniar A, Puente O, Oladipupo I, Crowther G, Zareba AM, Yi Z, Scully I, Gomme E, Koury K, Kitchin N, Allen PS, Anderson AS, Gurtman A, Lindert K. A Phase 1/2 Randomized Study to Evaluate the Safety, Tolerability, and Immunogenicity of Nucleoside-Modified Messenger RNA Influenza Vaccines in Healthy Adults. Vaccines (Basel). 2025 Apr 3;13(4):383. doi: 10.3390/vaccines13040383.
• To obtain contact information for a study center near you, click here.Link provided by the sponsor.
• Individual participant dataSharing planned: Yes. Pfizer will provide access to individual de-identified participant data and related study documents (e.g. protocol, Statistical Analysis Plan (SAP), Clinical Study Report (CSR)) upon request from qualified researchers, and subject to certain criteria, conditions, and exceptions. Further details on Pfizer's data sharing criteria and process for requesting access can be found at: https://www.pfizer.com/science/clinical_trials/trial_data_and_results/data_requests.

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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.

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