CI

At a glance

ClinicalIndex Comparison Record
Phase 2Completed· 260 enrolled
Drug / intervention
aH5N6c on Day 1 +2 morebiological
Likely dose
aH5N6c on Day 1 7.5 μgfrom record
Structured eligibility isn't available for this trial yet — see the full criteria in the Eligibility tab below.

Standardized by ClinicalIndex from the ClinicalTrials.gov record · verify against the source.

Search/NCT05422326
NCT05422326Phase 2Completed

A Phase 2, Randomized, Study to Evaluate Safety and Immunogenicity of One or Two Heterologous Booster Vaccinations With an MF59-adjuvanted, Cell Culture-derived H5N6 Influenza Vaccine in Adults Primed With MF59-adjuvanted, Cell Culture-derived H5N1 Influenza Vaccine or Unprimed

Seqirus·interventional·Posted Jun 16, 2022·Updated May 13, 2026

In Brief

A Phase 2 clinical trial evaluating aH5N6c on Day 1, aH5N6c on Day 22, and 1 other intervention for Influenza, Human and 7 related conditions. Completed, enrolled 260 participants across 18 sites.

Detailed Summary

This is a Phase 2, randomized, multi-center study in approximately 300 adults who received 2 doses of aH5N1c or placebo in and completed the parent study V89\_18 in the \<65 years of age cohort. The study investigates whether two priming doses of MF59-adjuvanted H5N1 cell culture-derived vaccine (aH5N1c) followed by one or two booster vaccinations with a MF59-adjuvanted H5N6 cell culture derived vaccine (aH5N6c) 3 weeks apart elicit immune responses to the antigens used for priming (H5N1) and boosting (H5N6) after first and second heterologous booster vaccination. Eligible subjects, who received 2 doses of aH5N1c in the parent study V89\_18 are randomized in a 1:1 ratio to receive either two aH5N6c vaccinations, 3 weeks apart (group 1) or an aH5N6c vaccination on Day 1 and saline placebo on Day 22 (group 2). Eligible subjects, who received placebo in the parent study will receive two aH5N6c vaccinations, 3 weeks apart (group 3). After the second vaccine administration, subjects are monitored for approximately 6 months for safety and antibody persistence. The total study duration will be approximately 7 months per subject.

Study Details

Study Typeinterventional
Allocation--
Masking--
Primary Purpose--
CountriesUnited States
Collaborators--

Timeline

Phase 2CompletedFinished
2023202420252026
First PostedJun 16, 2022
Enrollment StartJul 18, 2022
Primary CompletionOct 24, 2022
Study CompletionMar 24, 2023
TodayJul 2, 2026
Enrollment to primary: 3 monthsPosted 4.0 years ago

Interventions

aH5N6c on Day 1biological

MF59-adjuvanted cell-culture derived subunit inactivated monovalent A/H5N6 vaccine (aH5N6c) for intramuscular (IM) administration, containing 7.5 μg H5N6 hemagglutinin (HA) (A/Guangdong/18SF020/2018 (H5N6)-like) + 0.25 mL MF59 (approximately 0.5 mL total volume)

aH5N6c on Day 22biological

MF59-adjuvanted cell-culture derived subunit inactivated monovalent A/H5N6 vaccine (aH5N6c) for intramuscular (IM) administration, containing 7.5 μg H5N6 HA (A/Guangdong/18SF020/2018 (H5N6)-like) + 0.25 mL MF59 (approximately 0.5 mL total volume) given 3 weeks after the first aH5N6c vaccination

Placebo on Day 22biological

Saline placebo (sterile, 0.5 mL) given 3 weeks after the aH5N6c vaccination