A universal flu vaccine that could protect against all types of flu is closer to being developed, say scientists at Imperial College London.
After studying people who seem to resist the virus, scientists at the college say they have developed a ‘blueprint’ for a universal flu vaccine.
National Heart and Lung Institute at Imperial College London professor Ajit Lalvani, who lead the study, said new strains of flu are continuously emerging, so the ‘Holy Grail’ is to create a universal vaccine that would be effective against all strains of flu.
During the 2009 swine flu pandemic, researchers asked volunteers to donate blood samples and report any symptoms they experienced over the next two flu seasons.
Those who avoided severe illness were discovered to have more CD8 T cells, a type of virus-killing immune cell, in their blood at the start of the pandemic.
Scientists hope they can create a vaccine that stimulates the body to produce more of these cell preventing flu viruses from causing serious disease, including new strains that cross into humans from birds and pigs.
Seasonal flu kills between 250,000 and 500,000 people each year and new pandemics have the potential to take doctors by surprise and kill large numbers of people.
Current vaccines available are always one-step behind because they need to be changed each year as new viruses with different surface structures evolve.
"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," Lalvani added.
"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."
He added that they already know how to stimulate the immune system to make CD8 T cells by vaccination and so can design a vaccine to prevent people getting symptoms and transmitting infection to others.
"This could curb seasonal flu annually and protect people against future pandemics," he said.
The full findings of the study are published in Nature Medicine.
Image: Seasonal flu kills between 250,000 and 500,000 people each year and new pandemics have the potential to take doctors by surprise and kill large numbers of people. Photo: courtesy of Antonio Jimenez Alonzo.