Science for All | What is M2e?

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The M2 protein is considered to be a holy grail of designing a universal flu vaccine. The seasonal influenza strains mutate rapidly and new strains of the virus proliferate. This makes it very difficult to make a vaccine that can consistently generate a sufficient degree of immunity.

The M2e peptide is a section of the influenza virus that is conserved, meaning it doesn’t undergo too many mutations. Researchers have observed through the years that the M2e peptide region is pretty much unchanged across the several kinds of influenza A strains. Therefore, it is possible to design a vaccine that targets this peptide and prime the immune system to generate antibodies.

For this reason, M2e has for years been seen as a leading universal flu candidate. However, it has a limited ability to trigger a strong and long-lasting immune response and this has represented a major roadblock in its clinical development.

Recently researchers have reported a novel vaccine platform to deliver M2e to immune cells. By deploying this platform, a single shot vaccine containing M2e was able to trigger long-lasting immune responses that could protect effectively against multiple strains of the flu.

The team was also able to demonstrate that this vaccination approach significantly enhanced protective immune responses in the context of pre-existing flu immunity-- a situation particularly relevant in adult and elderly populations, where individuals have been exposed to flu viruses multiple times in the past and have low levels of M2e-specific antibodies in their blood circulation.

This vaccine approach has the potential to minimise the amount of M2e vaccine antigen (substance that triggers the body’s immune response against that itself) and the need for strong adjuvants (a substance which enhances the body’s immune response to an antigen), reducing potential side-effects, particularly in more vulnerable populations.