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Active, not recruiting Phase 1Phase 2 Interventional Accepts healthy volunteers

Study to Evaluate the Safety and the Immunogenicity of a Second Generation Structurally Designed mRNA Vaccine Candidate Against Pandemic Influenza H5 HA Strain in Healthy Adult Participants Aged 18 Years and Older

ClinicalTrials.gov ID: NCT06907511

Public ClinicalTrials.gov record NCT06907511. Field values are reproduced from the official study page; the official ClinicalTrials.gov record remains the source of truth for eligibility, enrollment, and contact information.

ClinicalTrials.gov public records Last synced Sep 9, 2026, 4:14 AM EDT

Data is sourced from official ClinicalTrials.gov public API records. Always review the official ClinicalTrials.gov record for the latest information.

Official title

A Phase 1/2, Parallel-group, Randomized, Modified Double-blind, Placebo-controlled, Multi-center, Dose Ranging Study to Evaluate the Safety and Immunogenicity of a Second Generation Structurally Designed Pandemic Influenza H5 HA mRNA Vaccine in Healthy Adults Aged 18 Years and Older

Brief summary

Reproduced verbatim from the official ClinicalTrials.gov record. Not medical advice.

The purpose of this phase 1/2 study is to investigate the safety and immunogenicity of different doses (high, medium and low) of a second generation structurally designed (SD2) H5 messenger ribonucleic acid (mRNA) vaccine against pandemic H5 influenza virus (pandemic flu H5 hemagglutinin (HA) mRNA SD2) in healthy younger and older adults. The study will aim to identify the appropriate dose for further clinical development of a potential pandemic response vaccine. The study also includes an extension phase for one of the 3 dose levels of the pandemic flu H5 HA mRNA SD2 vaccine to collect additional safety and the immunogenicity data for this specific dose of the vaccine. During this Extension Phase, an additional 480 participants will be randomized according to a 1:1 ratio and stratified by age (≥ 18 to \< 65 years and ≥ 65 years) to receive either the low dose of the pandemic flu H5 HA mRNA DS2 vaccine (Group 1) or placebo (Group 4). This extension will enhance the safety database and improve precision of the immunogenicity results for the selected dose while preserving the original study design integrity. The study duration per participant will be approximately 13 months. There will be two injections of placebo or pandemic flu H5 mRNA vaccine 21 days apart at high, medium and low doses. Study visits/contact include: 7 study visits and 1 telephone call. Vaccination visits (including blood samples) will occur at Day 01 and Day 22. Short-term follow-up visits (including blood samples) will occur 8 and 21 days after each injection. Participants will be also followed up (including blood samples) at 3 and 6 months after 2nd injection, and at 12 months after 2nd injection for safety.

Study identification

NCT ID
NCT06907511
Recruitment status
Active, not recruiting
Study type
Interventional
Phase
Phase 1, Phase 2
Lead sponsor
Sanofi
Industry
Enrollment
720 participants

Conditions and interventions

Eligibility (public fields only)

Age range
18 Years and older
Sex
All
Healthy volunteers
Accepts healthy volunteers

This page does not interpret eligibility. Detailed inclusion and exclusion criteria are on the official ClinicalTrials.gov record.

Study timeline

Start date
Apr 16, 2025
Primary completion
Nov 30, 2026
Completion
Nov 30, 2026
Last update posted
Jan 15, 2026

2025 – 2026

United States locations

U.S. sites
13
U.S. states
10
U.S. cities
13
Facility City State ZIP Site status
Velocity Clinical Research - San Diego- Site Number : 8400013 La Mesa California 91942
Accel Research Sites Network - DeLand Clinical Research Unit- Site Number : 8400002 DeLand Florida 32720
Accel Research Sites - Lakeland Clinical Research Unit- Site Number : 8400006 Lakeland Florida 33803
Accel Research Sites - St. Petersburg - Largo- Site Number : 8400004 Largo Florida 33777
Accel Research Site - NeuroStudies.net, LLC - ERN - PPDS- Site Number : 8400003 Decatur Georgia 30030-2627
QUEST Research Institute- Site Number : 8400014 Bingham Farms Michigan 48334
Velocity Clinical Research - Norfolk- Site Number : 8400015 Norfolk Nebraska 68701
Velocity Clinical Research - Omaha- Site Number : 8400012 Omaha Nebraska 68134
Velocity Clinical Research - Springdale- Site Number : 8400010 Cincinnati Ohio 45246
Coastal Carolina Research Center- Site Number : 8400001 North Charleston South Carolina 29406
Olympus Clinical Research - Sugar Land- Site Number : 8400009 Sugar Land Texas 77479
Velocity Clinical Research - Salt Lake City- Site Number : 8400011 West Jordan Utah 84088
Charlottesville Medical Research- Site Number : 8400005 Charlottesville Virginia 22911

Site contact phone numbers, emails, and investigator names are intentionally not displayed here. Open the official ClinicalTrials.gov record for site contact information.

About this trial record page

What this page shows
Public field values for ClinicalTrials.gov record NCT06907511, including study identification, conditions, interventions, eligibility (age, sex, healthy volunteer), timeline, and U.S. site list.
What this page does not do
No medical advice, eligibility judgments, treatment recommendations, study quality scoring, or AI-generated medical summaries. No site contact phone numbers, emails, or investigator names.
Where the data comes from
Sourced from the official ClinicalTrials.gov public API. The official record is the source of truth.
Last refresh
Last update posted Jan 15, 2026 · Synced Sep 9, 2026

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Open the official record

The complete protocol, eligibility criteria, and contact information for NCT06907511 live on ClinicalTrials.gov.

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