In short
mRNA Encoding Influenza A Virus, subtype H3N2, strain A/Darwin/6/2021, hemagglutinin glycoprotein is an investigational mRNA vaccine component that targets the H3N2 strain of seasonal influenza. It is being studied as part of combination mRNA vaccines that aim to protect against both influenza and COVID-19.
mRNA Encoding Influenza A Virus, subtype H3N2, strain A/Darwin/6/2021, hemagglutinin glycoprotein is an investigational mRNA vaccine component that encodes the hemagglutinin glycoprotein of the H3N2 influenza A strain A/Darwin/6/2021. It is being studied as part of combination mRNA vaccines that aim to protect against both influenza and COVID-19. The registered trial listed in the EU Clinical Trials Information System plans to enrol 410,000 adults aged 65 years and older to compare a combined influenza/COVID-19 mRNA vaccine against separate influenza and COVID-19 vaccines.
Key points
- mRNA Encoding Influenza A Virus is an investigational vaccine component targeting the H3N2 influenza strain.
- The registered trial is a phase 3 pragmatic randomised study in adults aged 65 years and older.
- The trial plans to enrol 410,000 participants.
- The study compares a combined influenza/COVID-19 mRNA vaccine with separate co-administered vaccines.
- Primary outcomes measure medically attended influenza or COVID-19 and related hospitalisation.
- The trial is currently authorised in the EU Clinical Trials Information System.
What is mRNA encoding influenza A virus?
mRNA Encoding Influenza A Virus, subtype H3N2, strain A/Darwin/6/2021, hemagglutinin glycoprotein is a messenger RNA (mRNA) vaccine component. mRNA vaccines work by providing genetic instructions that teach cells to make a specific viral protein, which then triggers an immune response. This component encodes the hemagglutinin glycoprotein of the H3N2 influenza A strain A/Darwin/6/2021. It is not authorised as a standalone medicine; it is an investigational substance being studied as part of combination mRNA vaccines that also target COVID-19.
How does mRNA encoding influenza A virus work?
mRNA vaccines deliver genetic instructions to cells, which then produce a specific viral protein. The immune system recognises this protein as foreign and builds defences against it. For this substance, the mRNA encodes the hemagglutinin glycoprotein of the H3N2 influenza A strain A/Darwin/6/2021. Hemagglutinin is a surface protein of the influenza virus that helps it enter cells. By producing this protein, the vaccine aims to train the immune system to recognise and fight the H3N2 influenza strain. A published analysis of two phase 3 randomised clinical trials of an mRNA-based seasonal influenza vaccine in adults reported results on hemagglutination inhibition titers, a laboratory measure of antibody response against influenza.
Which conditions is it used or studied for?
- Influenza infection — the registered trial studies prevention of influenza infection in adults aged 65 years and older.
- SARS-CoV-2 infection — the trial also studies prevention of COVID-19 in the same population, as the combination vaccine targets both viruses.
How is mRNA encoding influenza A virus given?
The registered trial lists the combination vaccine mCombriax (mRNA-1083) as a dispersion for injection in a pre-filled syringe, given by intramuscular injection. The trial record does not describe a standalone formulation of mRNA Encoding Influenza A Virus, subtype H3N2, strain A/Darwin/6/2021, hemagglutinin glycoprotein.
What do the clinical trials show?
One clinical trial is registered in the EU Clinical Trials Information System for the combination vaccine containing this substance. The trial is a phase 3, pragmatic, randomised study that plans to enrol 410,000 adults aged 65 years and older. It is currently authorised.
Who can take part in these trials?
The registered trial enrols adults aged 65 years and older. The trial record does not list additional inclusion or exclusion criteria.
What are the trials measuring?
The primary endpoints of the registered trial are the occurrence of medically attended influenza and/or COVID-19, and influenza and/or COVID-19 hospitalisation. The study aims to evaluate the comparative vaccine effectiveness of the combination vaccine mCombriax versus same-day co-administration of a high-dose influenza vaccine and a COVID-19 mRNA vaccine.
What side effects are known?
The supplementary source provided does not report side effects for this specific vaccine component. No side effect information is therefore included here.