NotablePrimary endpoints: details revised at 2 of 14 entriesShow 5 more changesShow less
Eligibility criteria expanded, about 4 words
Enrollment closed, study ongoing
Final enrollment: 360 participants (planned 570)
Secondary endpoints: details revised at 1 of 5 entries
Site details revised at 6 of 6 sites
NotableRecruitment opened
Trial sites expanded: 0 → 6 locations
Start date changed from estimate of Apr 13, 2026 to Apr 15, 2026
v2
Study First Submitted
Notable: the plan changed
Endpoints
Primary
Presence of any unsolicited systemic Adverse Events (AEs) reported within 30 minutes after vaccination
Timeframe: On Day 1
Presence of solicited injection site reactions (ie, injection site pain, injection site erythema, injection site swelling, pre-listed in participant's diary and in the eCRF (electronic case report form)) occurring through 7 days after each vaccination
Timeframe: Day 1 through day 8
Presence of solicited systemic reactions (ie, fever, headache, and only new or worsened fatigue, myalgia, arthralgia, and chills pre-listed in the participant's diary and in the eCRF) occurring through 7 days after each vaccination
Timeframe: Day 1 through day 8
Presence of unsolicited AEs reported through 20 days after the first vaccination and after the second vaccination for IMPs with the Flu H5 antigen
Timeframe: Day 1 through day 21
Presence of unsolicited AEs reported through 28 days after vaccination for IMPs with the RSV antigen
Timeframe: Day 1 through day 29
Presence of SAEs (Serious Adverse Events) and AESIs (Adverse Events of Special Interest) throughout the study (ie, through 6 months after vaccination)
Timeframe: SAE: Screening day through day 202 (IMPs containing Flu H5 antigen), Screening day through day 181 (IMPs containing RSV antigen); AESI: Day 1 through day 202 (IMPs containing Flu H5 antigen), Day 1 through day 181 (IMPs containing RSV antigen)
Presence of out-of-range biological test results (including shift from baseline values) through 7 days after each vaccination
Timeframe: Screening through day 8
Presence of AEs leading to study discontinuation throughout the study (ie, through 6 months after vaccination)
Timeframe: Screening through day 202 (IMPs containing Flu H5 antigen), Screening through day 181 (IMPs containing RSV antigen)
RSV A and RSV B serum nAb (neutralizing antibodies) titers at pre-vaccination and 28 days post-vaccination in all participants receiving IMPs with the RSV antigen
Timeframe: Day 1 and day 29
Flu H5 antibody (Ab) titer measured by hemagglutination inhibition (HAI) at pre-vaccination and 21 and 42 days post-vaccination in all participants receiving IMPs with the Flu H5 antigen
Timeframe: Day 1, day 22 and day 43
Hemagglutination Inhibition (HAI) geometric mean titer ratio at 21 and 42 days post-vaccination relative to pre-vaccination for all participants receiving IMPs with the Flu H5 antigen
Timeframe: Day 1, day 22 and day 43
Seroconversion rate based on Hemagglutination inhibition (HAI) antibody titers at pre-vaccination and 21 and 42 days post-vaccination in all participants receiving IMPs with the Flu H5 antigen
Timeframe: Day 1, day 22 and day 43
Proportion of participants with Hemagglutination Inhibition (HAI) antibody titer ≥40 at pre-vaccination and 21 and 42 days post-vaccination in all participants receiving IMPs with the Flu H5 antigen
Timeframe: Day 1, day 22, and day 43
Proportion of participants with detectable HAI antibody titer ≥10 at pre-vaccination and 21 and 42 days post-vaccination in all participants receiving IMPs with the Flu H5 antigen
Timeframe: Day 1, day 22, and day 43
Secondary (5)
Geometric mean neutralizing antibody titers measured by Neutralization Assay (NT) at pre-vaccination and 21 and 42 days post-vaccination in all participants receiving IMPs with the Flu H5 antigen
Neutralizing antibody titer ratio at pre-vaccination and 21 and 42 days post-vaccination in all participants receiving IMPs with the Flu H5 antigen
Proportion of participants with neutralizing antibody titers ≥20, ≥40, and ≥80 at pre-vaccination and 21 and 42 days post-vaccination in all participants receiving IMPs with the Flu H5 antigen
Proportion of participants with detectable neutralizing antibody titers ≥10 at pre-vaccination and 21 and 42 days post-vaccination in all participants receiving IMPs with the Flu H5 antigen
Proportion of participants with ≥2-fold and ≥4-fold increase in neutralizing antibody titers at pre-vaccination and 21 and 42 days post-vaccination in all participants receiving IMPs with the Flu H5 antigen
Arms and interventions
Stage 1, Arm 1Experimental
Participants will receive a single IM (Intramuscular) injection on day 1 and day 22 of the H5 Flu vaccines according to their randomization schedule.
Stage 1, Arm 2Experimental
Participants will receive a single IM (Intramuscular) injection on day 1 and day 22 of the H5 Flu vaccines according to their randomization schedule.
Stage 1, Arm 3Experimental
Participants will receive a single IM (Intramuscular) injection on day 1 and day 22 of the H5 Flu vaccines according to their randomization schedule.
Stage 1, Arm 4Experimental
Participants will receive a single IM (Intramuscular) injection on day 1 of the RSV vaccines according to their randomization schedule.
Stage 1, Arm 5Experimental
Participants will receive a single IM (Intramuscular) injection on day 1 of the RSV vaccines according to their randomization schedule.
Stage 1, Arm 6Experimental
Participants will receive a single IM (Intramuscular) injection on day 1 of the RSV vaccines according to their randomization schedule.
Stage 2, Arm 1Experimental
Participants will receive a single IM (Intramuscular) injection on day 1 and day 22 of the H5 Flu vaccines according to their randomization schedule.
Stage 2, Arm 2Experimental
Participants will receive a single IM (Intramuscular) injection on day 1 and day 22 of the H5 Flu vaccines according to their randomization schedule.
Stage 2, Arm 3Experimental
Participants will receive a single IM (Intramuscular) injection on day 1 and day 22 of the H5 Flu vaccines according to their randomization schedule.
Stage 2, Arm 4Experimental
Participants will receive a single IM (Intramuscular) injection on day 1 and day 22 of the H5 Flu vaccines according to their randomization schedule.
Stage 2, Arm 5Experimental
Participants will receive a single IM (Intramuscular) injection on day 1 and day 22 of the H5 Flu vaccines according to their randomization schedule.
Stage 2, Arm 6Experimental
Participants will receive a single IM (Intramuscular) injection on day 1 and day 22 of the H5 Flu vaccines according to their randomization schedule.
