Table of Contents
- Trial overview
- Who participated
- What was studied
- Study endpoints and measurements
- Trial phase and design
- Key trial details
Trial overview
The main study of A/(H3N2)-LIKE VIRUS ANTIGEN was a Phase 3, interventional trial called the Celljuvant study.[1] It was completed and enrolled 6,300 participants.[1]
The study looked at an adjuvanted quadrivalent subunit inactivated cell-derived influenza vaccine and compared immune responses across different vaccine lots and against other influenza vaccine products.[1]
Who participated
The trial studied adults aged 50 years and older.[1] Participants were either healthy or had stable comorbidities, which means other long-term health conditions that increase the risk of flu complications but were not changing quickly.[1]
This target group is important because older adults are more likely to have serious problems from influenza infection.[1]
What was studied
The study first tested lot-to-lot consistency of 3 consecutive vaccine lots of aQIVc HD, meaning the researchers checked whether different batches gave similar immune responses.[1] This helps show that the vaccine is produced consistently.[1]
The trial then tested immunological noninferiority of aQIVc HD versus QIVr and versus aQIV.[1] Noninferiority means the study aimed to show that the immune response was not worse than the comparison vaccines by more than a set amount.[1]
The immune response was measured for each vaccine strain, including the H3N2-related strain listed in the source data as A/DARWIN/9/2021 (H3N2)-LIKE STRAIN.[1]
Study endpoints and measurements
The main endpoints were immunogenicity responses, which means how strongly the body made antibodies after vaccination.[1]
Day 29 Geometric Mean Titer (GMT): this measures the average antibody level in the group 29 days after vaccination.[1]
Day 29 Geometric Mean Titer Ratio (GMTr): this compares antibody levels between vaccine lots or study groups.[1]
Day 1 to Day 29 Seroconversion Rate (SCR): this shows the percentage of people whose antibody levels rose enough to count as a clear immune response.[1]
SCR difference: this compares the rise in antibody response between study groups.[1]
These results were measured with a hemagglutination inhibition assay, a lab test used to measure influenza antibodies.[1]
Trial phase and design
This was a Phase 3 interventional study, which means participants received study vaccines and the research was done in a large group of people.[1] The study design was sequential: first it checked consistency between vaccine lots, and then it compared immune responses against other influenza vaccines.[1]
The source data also shows that the study included several influenza vaccine components and related strains, which were used to assess immune response across the vaccine’s strains.[1]
