Scientists claim they have discovered the ‘blueprint’ for a universal flu vaccine.
Using the recent swine flu pandemic as a ‘natural experiment’, researchers from Imperial College London uncovered a specific part of the immune system which offers some flu protection.
Current vaccines are only effective for a while because the flu virus is constantly mutating.
But the researchers say they have found ‘key fragments’ in the internal core of the virus, which does not change.
Study lead Professor Ajit Lalvani explained: "The immune system produces these CD8 T cells in response to usual seasonal flu. Unlike antibodies, they target the core of the virus, which doesn't change, even in new pandemic strains. The 2009 pandemic provided a unique natural experiment to test whether T cells could recognise, and protect us against, new strains that we haven't encountered before and to which we lack antibodies.
"Our findings suggest that by making the body produce more of this specific type of CD8 T cell, you can protect people against symptomatic illness. This provides the blueprint for developing a universal flu vaccine.”
At the start of the 2009 swine flu pandemic, 342 staff and students at Imperial donated blood samples and reported any symptoms over the next two flu seasons.
Those who avoided sever illness had more CD8 T cells – a type of virus-killing immune cell – at the start of the pandemic.
Creating a vaccine that could stimulate production of CD8 T cells could be a step towards a universal vaccine, the research published in Nature Medicine concluded.
However, the researchers did admit that it is “generally harder” to develop a T-cell reaction than provoke an antibody response, as with typical vaccines.
Professor John Oxford from Queen Mary University of London, said: "This sort of effect can't be that powerful or we'd never have pandemics. It's not going to solve all the problems of influenza, but could add to the range of vaccines.
"It's going to be a long journey from this sort of paper to translating it into a vaccine that works."