Scientists Closer to a Universal Flu Vaccine
- By BSTQ Staff
Recent studies of the flu virus are bringing hope that seasonal flu vaccines will be replaced with long-lasting universal vaccines. Currently, flu vaccines are updated each year with three and soon-to-be four of the most prevalent circulating virus strains. They protect people from the virus strains by letting them make antibodies in advance. The vaccines contain fragments from the tip of a protein on the surface of the virus, called hemagglutinin, B cells that encounter the vaccine fragments and learn how to make antibodies against them. Therefore, these vaccines can protect against only flu viruses with a matching strain.
Dr. Sarah Gilbert and her colleagues at Oxford University are trying to build a T cell-based vaccine that could attack a part of the flu virus that changes little from year to year. They’ve found that when T cells learn to recognize proteins from one kind of virus, they can attack many other kinds. It appears that the flu proteins that infected cells select to put on display evolve very little. The scientists are testing a vaccine that prepares T cells to mount a strong attack against flu viruses by engineering a virus that can infect cells but cannot replicate. As a result, infected cells put proteins on display, but people who receive the vaccine do not get sick. In a clinical trial, 11 vaccinated individuals and 11 unvaccinated individuals were given the vaccine and then exposed to the flu. Two of the vaccinated people became ill, while five unvaccinated ones did.
While the Oxford researchers are focusing on T cells, other researchers are developing vaccines that can generate antibodies that are effective against many flu viruses, or perhaps all of them. The goal, according to Gary J. Nabel, director of the Vaccine Research Center at the National Institute of Allergy and Infectious Diseases, is for individuals to receive two shots when they are young and then boosters later in life.
A universal vaccine would not only help in the fight against seasonal flu outbreaks, but Dr. Gilbert argues that it could potentially have greater benefit for protection against pandemic flu viruses. Currently, scientists don’t have a vaccine for a new pandemic strain until an outbreak is well under way. An effective universal vaccine would already be able to fight it.
