Scientists Test Universal Flu Vaccine in Mice

If finding bears out in humans, new vaccines might not have to be developed every year

TUESDAY, July 21, 2015 (HealthDay News) -- Scientists report that a universal flu vaccine in mice protected the animals against eight different flu strains.

If the vaccine works in humans, scientists might not have to develop new flu vaccines every year, the researchers said.

The findings were reported July 21 in the journal mBio.

Currently, a vaccine is created each year to protect against the handful of flu strains that are predicted to be the most common during that flu season. And the vaccine makeup is determined months in advance so that manufacturers have time to make the millions of doses needed.

"The reason researchers change the vaccine every year is that they want to specifically match the vaccine to the particular viruses that are circulating, such as H1N1. If the vaccine is just a little bit different to the target virus, it is not expected to offer much protection," explained lead investigator Dr. Jeffery Taubenberger, chief of the viral pathogenesis and evolution section in the laboratory of infectious diseases at the U.S. National Institute of Allergy and Infectious Diseases (NIAID).

"What we have done is design a strategy where you don't have to think about matching the vaccine antigen to the virus at all," Taubenberger said in a news release from the American Society for Microbiology.

The NIAID scientists developed a vaccine meant to protect against a number of flu strains. The vaccine protected 95 percent of mice against eight different flu strains, compared with 5 percent of mice that received mock vaccinations.

The vaccine was effective for at least 6 months and worked well in older mice. The latter finding is especially important because elderly people are particularly susceptible to severe illness from the flu, and current vaccines are less effective in seniors than in younger people, the researchers said.

"These initial findings are very positive, and suggest a promising and practical strategy for developing a vaccine with amazing, broad protection," Taubenberger said.

However, results from animal studies frequently don't produce similar results in humans. The team said it will test ferrets next, and then begin early human trials.

During the 2014-2015 flu season, the chosen vaccine was a mismatch for the strains that were circulating. So, it was only 18.6 percent effective against the predominant strain, according to the U.S. Centers for Disease Control and Prevention. U.S. health officials have said they have ramped up next season's shots for broader protection.

More information

The U.S. Centers for Disease Control and Prevention has more about flu vaccination.

SOURCE: American Society for Microbiology, news release, July 21, 2015
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