In short
Influenza B virus inactivated hemagglutinin is a vaccine component derived from influenza B viruses. It is used in influenza vaccines to help the body build protection against flu caused by influenza B strains. The clinical trial data reviewed here includes one authorised Phase 1/2 study with 250 healthy participants, investigating a combination vaccine containing this hemagglutinin.
Influenza B virus inactivated hemagglutinin is a seasonally-specific component of influenza vaccines. It is derived from influenza B viruses and is inactivated so that it cannot cause infection. When included in a vaccine, it helps the immune system recognise and defend against influenza B viruses.
Key points
- Influenza B virus inactivated hemagglutinin is a component of influenza vaccines that exposes the immune system to parts of the influenza B virus.
- One authorised Phase 1/2 clinical trial with 250 healthy participants is investigating a combination influenza vaccine containing this hemagglutinin.
- The trial is randomised, double-blind, and reference-controlled, comparing different vaccine combinations and a licensed vaccine.
- The main goal is to assess safety and immunogenicity (how well the vaccine triggers an immune response) after intramuscular injection.
- The study measures solicited local and systemic reactions for seven days after vaccination, as well as unsolicited adverse events for 28 days.
- The trial is registered in the EU Clinical Trials Information System under number 2026-526939-19-00.
What is influenza B virus inactivated hemagglutinin?
Influenza B virus inactivated hemagglutinin is a vaccine antigen. Hemagglutinin is a protein found on the surface of influenza viruses that allows the virus to enter cells. In vaccines, the hemagglutinin is inactivated (using formaldehyde or UV light) so it cannot cause disease, but it can still stimulate an immune response. The substance is classified as an approved vaccine component and is typically included as one part of a multivalent influenza vaccine that also contains influenza A virus antigens.
In the clinical trial data, this hemagglutinin is part of a combination vaccine being studied under the development name GC-IIV, which contains 15µg of hemagglutinin from each influenza strain included.
How does influenza B virus inactivated hemagglutinin work?
Vaccines provide protection from influenza by exposing the immune system to the virus or parts of the virus. This exposure stimulates an immunological defence against future exposure to the virus, or "antigen". When the inactivated hemagglutinin is injected, the immune system learns to recognise it and produces antibodies. If the person later encounters the actual influenza B virus, these antibodies can help prevent infection or reduce the severity of illness.
Which conditions is influenza B virus inactivated hemagglutinin used or studied for?
- Influenza disease — The clinical trial investigates prevention of influenza disease in healthy participants using a combination vaccine containing this hemagglutinin.
Influenza B virus inactivated hemagglutinin is also a component of licensed seasonal influenza vaccines, where it contributes to protection against influenza B strains.
How is influenza B virus inactivated hemagglutinin given?
In the clinical trial, the vaccine containing influenza B virus inactivated hemagglutinin is administered by intramuscular (IM) injection. The trial includes a combination vaccine (GC-IIV) containing 15µg of each hemagglutinin, mixed with another investigational vaccine component called OVX836 at a dose of 480µg. The comparison arms include GC-IIV alone, OVX836 alone, GC-IIV and OVX836 given concomitantly, and a licensed reference trivalent influenza vaccine (Vaxigrip).
What do the clinical trials show?
One clinical trial has been identified in the registry data. It is a Phase 1/2, first-in-human, randomised, double-blind, reference-controlled study. The trial is authorised and plans to enrol 250 healthy participants.
The study compares five groups: the extemporaneously mixed combination vaccine (GC-IIV plus OVX836), GC-IIV and OVX836 given concomitantly at separate injection sites, GC-IIV alone, OVX836 alone, and the licensed reference vaccine Vaxigrip.
The primary outcomes focus on safety and reactogenicity. These include the number and percentage of participants reporting solicited local and systemic signs and symptoms during seven days after vaccination, unsolicited adverse events during 28 days after vaccination, serious adverse events (SAEs) during the whole study duration, adverse events of special interest (AESI) and/or new onset of chronic diseases (NOCDs), and deviations from normal values in safety laboratory tests during 28 days after vaccination.
What side effects are known?
The clinical trial is specifically designed to measure side effects, including solicited local reactions (such as pain or redness at the injection site) and systemic reactions (such as fever or fatigue) during the first seven days after vaccination. The study also monitors unsolicited adverse events for 28 days and serious adverse events for the entire study duration. Results from this trial are not yet available in the registry data.
Who can take part in these trials?
The trial enrols healthy participants. The study is described as first-in-human, meaning it is the first time this specific combination vaccine is being tested in people.