Scientists Closer to Developing a Universal Flu Vaccine, Study Suggests

By examining why some individuals seemed to resist the 2009 swine flu pandemic while others did not, researchers say they have made an important stride in developing a universal flu vaccine.

Recognizing an opportunity when it came, a team of scientists from Imperial College London acquired 342 of blood samples just as the pandemic got underway, and then asked participants to report any symptoms they experienced during the course of the next two flu seasons.

The results, published in the journal Nature Medicine, reveal a correlation between a person's ability to avoid becoming seriously sick and the number of CD8 T cells, a type of virus-killing immune cell, in their blood.

Based on these findings, the scientists hypothesize that a vaccine capable of stimulating the body to produce more of these cells could prevent all forms of flu viruses from resulting in serious illness.

"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," Ajit Lalvani, the school's National Heart and Lung Institute and study lead, said in a statement. "This provides the blueprint for developing a universal flu vaccine."

Currently, flu vaccines are designed to trigger the production of antibodies by the immune system that then recognize structures on the surface of the virus. Using this method, however, researchers must develop new vaccines as different surface structures evolve, leaving scientists perpetually one step behind the pathogen.

The new approach, in contrast, is designed to "target the core of the virus, which doesn't change, even in new pandemic strains."

"New strains of flu are continuously emerging, some of which are deadly, and so the Holy Grail is to create a universal vaccine that would be effective against all strains of flu," Lalvani said. "We already know how to stimulate the immune system to make CD8 T cells by vaccination. Now that we know these T cells may protect, we 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."