Researchers identified the molecules after subjecting healthy volunteers to flu infections. The team found that participants’ immune systems targeted a specific range of peptides, or protein building blocks, within the internal structure of the flu virus.
Harnessing the immune system’s response to the peptides could produce an all-encompassing multi-strain vaccine, the scientists believe.
Current vaccines produce an antibody response to surface molecules which alter rapidly to stay ahead of the immune system.
However, the internal peptides change very slowly and do not vary between strains. They also trigger a response from T-cells — white blood cell elements of the immune system — rather than antibodies.
A T-cell vaccine aimed at the molecules has the potential to provide long-term immunity against all major flu strains, including bird and swine viruses.
Study leader Dr Tom Wilkinson, from the University of Southampton, said: “We have found there is an important role for T-cells that recognise the flu virus, which if harnessed could protect against most or even all strains of seasonal and pandemic flu.
“Through this discovery we hope to improve vaccines for future strains of influenza, and potentially protect against the next pandemic. However there is more to do to translate these findings into new approaches to treatment.”
The research is published in the online edition of the journal Nature Medicine.