In short
mRNA Encoding Influenza A Virus, subtype H1N1, strain A/Wisconsin/67/2022, hemagglutinin glycoprotein, is an investigational mRNA vaccine component studied as part of a combined influenza and COVID-19 vaccine. In the EU Clinical Trials Information System, it appears within a Phase 3 trial that plans to enroll 410,000 adults aged 65 and older.
mRNA Encoding Influenza A Virus, subtype H1N1, strain A/Wisconsin/67/2022, hemagglutinin glycoprotein, is an investigational vaccine component. It encodes the hemagglutinin glycoprotein of an influenza A H1N1 strain. In the trial record described here, it is part of a combined influenza and COVID-19 mRNA vaccine called mCombriax (mRNA-1083).
Key points
- Phase 3 trial in adults aged 65 years and older
- Planned enrollment of 410,000 participants
- Studies prevention of medically attended influenza and/or COVID-19
- Also measures influenza and/or COVID-19 hospitalization
- Trial status is Authorised in the EU registry
- Compares the combined vaccine with separate influenza and COVID-19 vaccines
What is mRNA Encoding influenza A virus?
mRNA Encoding Influenza A Virus, subtype H1N1, strain A/Wisconsin/67/2022, hemagglutinin glycoprotein, is an investigational messenger RNA (mRNA) vaccine component. It carries the genetic code for the hemagglutinin glycoprotein of an influenza A H1N1 virus strain. In the EU Clinical Trials Information System (CTIS), it is recorded as part of an investigational combined influenza and COVID-19 mRNA vaccine. The trial registry lists the combined product under the name mCombriax (mRNA-1083). No marketing authorisation is recorded in the trial data, so the vaccine is considered investigational.
How does mRNA Encoding influenza A virus work?
The substance is an mRNA vaccine component. mRNA vaccines deliver a short piece of genetic code to cells, instructing them to produce a specific viral protein. In this case, the code encodes the hemagglutinin glycoprotein of an influenza A H1N1 strain. Hemagglutinin is a surface protein of the influenza virus that helps the virus enter cells. When the body produces this protein after vaccination, the immune system can learn to recognise it and build a response against the influenza virus. The trial record does not provide further details on the mechanism of action.
Which conditions is it used or studied for?
The trial record lists two conditions that the combined vaccine is studied for:
- Influenza infection — an infection caused by influenza viruses, which can lead to fever, cough, muscle aches and, in older adults, serious complications.
- SARS-CoV-2 infection — the infection that causes COVID-19, which can range from mild respiratory symptoms to severe illness requiring hospital care.
The trial focuses on prevention of these infections in adults aged 65 years and older.
How is mRNA Encoding influenza A virus given?
In the trial, the combined vaccine mCombriax is given as a dispersion for injection in a pre-filled syringe, by intramuscular injection. The trial record lists the dose as 1 milligram for the combined product. The comparator vaccines are also given by intramuscular injection. No other pharmaceutical forms are described in the trial data.
What do the clinical trials show?
The registry contains one trial for this substance: a Phase 3, pragmatic, randomized trial with a planned enrollment of 410,000 participants. The trial status is Authorised. It is an interventional study in adults aged 65 years and older. The trial compares the combined influenza and COVID-19 vaccine mCombriax against same-day co-administration of two separate vaccines: a high-dose influenza vaccine (Efluelda) and a COVID-19 mRNA vaccine (Spikevax).
The primary endpoints are the occurrence of medically attended influenza and/or COVID-19, and influenza and/or COVID-19 hospitalization. The trial measures comparative vaccine effectiveness, meaning how well the combined vaccine prevents these outcomes compared with the separate vaccines given at the same time.
What side effects are known?
The trial record does not provide information on side effects. No supplementary sources with safety data were included in the available material, so this section cannot be filled from the given data.