Researchers at St. Jude Children's Research Hospital recently found that seasonal flu vaccines may boost immune systems against multiple flu viruses and not just the viruses in the vaccine.
Scientists at the hospital tested the immune responses of study participants who had received their flu vaccines and found that the participants had a strong immune response against many different types of flu, including the H3N2 flu strain from 2010.
The study also showed that the participants had a strong immune response against flu strains that have not been included in flu vaccines.
The researchers then tested blood samples from 95 different bird scientists for immune responses against avian influenza. The researchers wanted to see whether exposure to different kinds of birds prompts different immune responses from humans.
They exposed the samples to proteins from multiple avian influenza virus strains (H3, H4, H5, H6, H7, H8 and H12) to observe how strongly the immune systems responded and which viruses would trigger a response.
They found that 77 percent of the participants’ antibodies strongly reacted against both the H3N2 influenza virus and the avian influenza viruses.
There were no differences in immune responses to different types of birds.
"[This finding] suggests that the seasonal flu vaccine boosts antibody responses and may provide some measure of protection against a new pandemic strain that could emerge from the avian population," Paul G. Thomas, senior author of the study and an associate member in the Department of Immunology at St. Jude, said. "There might be a broader extent of reactions than we expected in the normal human population to some of these rare viral variants."
The study findings were recently published in "mBio," the online journal of the American Society for Microbiology.