Scientists have leveraged on a novel vaccine platform to deliver M2e to immune cells. This allowed them to prove that a single shot immunization 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. This scenario is 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.