In short
Inactivated influenza virus H1N1 hemagglutinin is a vaccine component derived from the influenza A H1N1 virus. It is being studied in a Phase 1/2 clinical trial as part of a combination vaccine against influenza disease in 250 healthy participants. The trial is authorised and compares the combination vaccine with a licensed trivalent influenza vaccine.
Key points
- Phase 1/2 first-in-human trial authorised in the EU
- Studies a combination vaccine containing inactivated influenza virus H1N1 hemagglutinin and OVX836
- Enrols 250 healthy participants in a randomised, double-blind design
- Compares the combination against Vaxigrip, a licensed trivalent influenza vaccine
- Primary focus is safety and immunogenicity after intramuscular injection
What is inactivated influenza virus H1N1 hemagglutinin?
Inactivated influenza virus H1N1 hemagglutinin is a protein component of the influenza A H1N1 virus that has been inactivated so it cannot cause infection. Hemagglutinin is a surface protein of the influenza virus that allows the virus to attach to cells in the respiratory tract. In vaccines, inactivated hemagglutinin is used to teach the immune system to recognise the virus without causing disease. The hemagglutinin protein is known to undergo gradual changes over time, a process called antigenic drift, which is why influenza vaccines are updated periodically.
In the clinical trial described on this page, inactivated influenza virus H1N1 hemagglutinin is included as part of an investigational combination vaccine called GC-IIV, which contains 15 micrograms of hemagglutinin from each influenza strain included in the vaccine. This vaccine is being studied together with another investigational component, OVX836, a nucleoprotein-based vaccine candidate.
How does inactivated influenza virus H1N1 hemagglutinin work?
Hemagglutinin is the main target of neutralising antibodies against influenza. When inactivated hemagglutinin is injected, the immune system produces antibodies that bind to this surface protein. These antibodies can then block the virus from attaching to and entering cells if the person is later exposed to influenza. The hemagglutinin protein of H1N1 viruses has specific antigenic sites that can change over time through mutation, which can affect how well antibodies recognise the virus.
In the investigational combination vaccine, the inactivated hemagglutinin component is paired with OVX836, which targets a different viral protein called nucleoprotein. The rationale for combining the two is to stimulate a broader immune response than either component alone.
Which conditions is it used or studied for?
- Influenza disease — the clinical trial studies the vaccine component for the prevention of influenza disease, a respiratory illness caused by influenza viruses.
How is inactivated influenza virus H1N1 hemagglutinin given?
The vaccine containing inactivated influenza virus H1N1 hemagglutinin is administered by intramuscular injection. In the clinical trial, the combination vaccine is prepared by mixing GC-IIV with OVX836 immediately before administration, a process described as extemporaneous mixing. The GC-IIV component contains 15 micrograms of hemagglutinin from each influenza strain included in the vaccine.
What do the clinical trials show?
One clinical trial is registered for this vaccine component. 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 trial has five study arms. Participants receive either the extemporaneously mixed combination vaccine, GC-IIV and OVX836 given as separate injections at the same time, GC-IIV alone, OVX836 alone, or a licensed reference trivalent inactivated influenza vaccine called Vaxigrip.
The primary outcomes measured in the trial are the number and percentage of participants reporting solicited local and systemic signs and symptoms during seven days after vaccine administration, unsolicited adverse events during 28 days after vaccination, serious adverse events, adverse events of special interest, and clinically relevant deviations from normal safety laboratory values during 28 days after vaccination.
What side effects are known?
The clinical trial is designed to collect information on side effects, including solicited local reactions such as pain or redness at the injection site, systemic symptoms such as fever or fatigue, unsolicited adverse events, and serious adverse events. Because the trial is still ongoing and the vaccine combination is investigational, the side effect profile is not yet fully established.