This is a phase 1, multicenter, randomized, double-blind trial of two influenza A/H5 mRNA-based vaccines on healthy adult participants, 18-49 years of age. Stage 1 will serve as the open-label, dose finding stage. The first 10 participants will receive 12.5 mcg of H5 AC-Anhui RNA vaccine (Group 1), and the second 10 participants will receive 25 mcg of H5 AC-Anhui RNA vaccine (Group 2). After Protocol Safety Review Team (PSRT) review of reactogenicity and safety data through Day 8 for both Groups 1 and 2, another 10 participants may be enrolled to receive 50 mcg of H5 AC-Anhui RNA vaccine (Group 3). Safety data from 7 days after dose 2 for Groups 1 and 2 participants will be reviewed by the PSRT prior to clearing Group 3 participants for the second dose of vaccine. Individual participants will be followed for approximately 6 months following the second dose of vaccine. The primary objective is to assess the safety of two doses of H5 AC-Anhui RNA vaccine or H5-Astrakhan RNA vaccine administered intramuscularly in healthy adults (18-49 years). Once the Day 36 data from Group 3 are reviewed by the PSRT, a dose will be chosen (12.5 mcg, 25 mcg, or 50 mcg) for advancement to Stage 2 where 50 participants will be randomized 1:1 to receive either H5 AC-Anhui RNA (Group 4) or H5 Astrakhan RNA (Group 5) in a double-blinded manner.
Age range
18 Years – 49 Years
Sex
ALL
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The trial coordinator is the person who runs the study day to day. These cover the practical side — logistics, costs, and what taking part would actually mean for your life. The study team confirms whether you meet the criteria; these are questions to ask, not a sign you qualify.
A starting point for the conversation — always confirm anything about your own eligibility, costs, and care with the study team and your doctor.
Number and Percentage of participants experiencing any adverse events of special interest (AESI)
Timeframe: Through 90 days after second vaccination
Number and Percentage of participants experiencing any medically attended adverse events (MAAE)
Timeframe: Through 6 months following the second dose
Number and Percentage of participants experiencing any non-serious unsolicited adverse events (AEs)
Timeframe: Through 28 days following each dose
Number and Percentage of participants experiencing any serious adverse events (SAE)
Timeframe: Through 6 months following the second dose
Number and Percentage of participants experiencing new-onset chronic medical conditions (NOCMC)
Timeframe: Through 6 months following the second dose
Number and Percentage of participants experiencing solicited local reactogenicity adverse events (AEs)
Timeframe: Through 7 days following each dose
Number and Percentage of participants experiencing solicited systemic reactogenicity adverse events (AEs)
Timeframe: Through 7 days following each dose
Number and Percentage of participants with clinical laboratory adverse events (AEs)
Timeframe: Through 7 days following each dose