Table of Contents
- Overview of the trials
- Who the trials are for
- Study design and trial phase
- What the trials measure
- Trial list
- What these results mean for patients
Overview of the trials
These clinical trials are studying influenza vaccine interventions that include INFLUENZA INACTIVATED SPLIT VIRUS STRAIN A (H3N2) as part of the influenza vaccine mix.[1][2] The studies are focused on Influenza, Human and are designed to evaluate both immune response and safety.[1][2]
Both trials are Phase 2 studies, which means they test how well the study interventions work and continue to watch safety in a larger group of people.[1][2] The trial data show one study as completed and the other as authorised.[1][2]
Who the trials are for
The target population in both studies is adults 18 years of age and older.[1][2] No other age groups are described in the trial data, so the information here applies only to adults.[1][2]
The studies compare different vaccine products, including the influenza inactivated split virus strain A (H3N2) component and other influenza vaccine formulations listed in the trial records.[1][2] The source data do not give additional participant rules such as sex limits, health requirements, or exclusion criteria.[1][2]
Study design and trial phase
Both studies are interventional, meaning the researchers give a study intervention and then measure the results.[1][2] This design is used to see whether the vaccine response and safety profile meet the study goals.[1][2]
The first trial enrolled 770 participants and was completed.[1] The second trial enrolled 960 participants and is authorised.[2] Together, these studies show a fairly large adult testing program for influenza vaccine evaluation.[1][2]
What the trials measure
The main efficacy-related outcomes are antibody measures at Day 29, including antibody titer, fold increase in titer from Day 1 to Day 29, seroconversion, and seroprotection.[1][2] These are blood-based markers that help show whether the body made an immune response after the study intervention.[1][2]
The safety outcomes include solicited administration site or systemic events within 7 days, unsolicited adverse events within 28 days, serious adverse events within 6 months, adverse events of special interest within 6 months, medically attended adverse events within 6 months, and laboratory abnormalities at several time points.[1][2] In simple terms, the studies track both short-term reactions and longer-term safety signals after vaccination.[1][2]
The brief summaries say the studies aim to evaluate the humoral immune response and the safety and reactogenicity profile of the study interventions.[1][2] Humoral immune response means the antibody response in the blood.[1][2]
Trial list
- 2025-522278-35-00 — Phase 2, completed, 770 adults, focused on influenza immune response and safety.[1]
- NCT07204964 — Phase 2, authorised, 960 adults, focused on influenza immune response and safety.[2]
What these results mean for patients
For patients, these trials are mainly about learning whether the influenza vaccine study options can produce a strong antibody response in adults and whether they are safe to use.[1][2] The data do not report final clinical protection against influenza illness in the text provided, so the main results here are immune markers and safety checks.[1][2]
Because the studies are in adults 18 years and older, the findings are most relevant to adult influenza vaccination research.[1][2] The trial records also show that the researchers are watching for both common short-term events and less common longer-term safety outcomes.[1][2]



