A team led by a scientist of Indian origin has made a "blueprint" for a universal flu vaccine.

The influenza virus that causes flu is known to be one of the world’s most rapidly changing organisms. Flu vaccines become redundant after every season and aren’t effective against every strain causing cough, cold and other complications. So, scientists have to create new vaccines with new strains of the virus each year.

Now, a team led by professor Ajit Lalvani from the National Heart and Lung Institute at Imperial College London has used a 2009 pandemic virus strain to study why some people seem to resist severe illness, thereby stumbling upon a recipe to create the world’s first universal flu vaccine. Lavani asked volunteers to donate blood samples just as the swine flu pandemic was getting under way and report any symptoms they experienced over the next two flu seasons.

The scientists found those who avoided severe illness had more CD8 T cells, a type of virus-killing immune cell, in their blood at the start of the pandemic.

They believe a vaccine that stimulates the body to produce more of these cells could be effective at preventing flu viruses, including new strains that cross into humans from birds and pigs, from causing serious disease.

"The immune system produces these CD8 T cells in response to usual seasonal flu," Lalvani said. "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."