Flu Vaccine With Both B Strains May Offer Better Protection
Adding second strain to seasonal shot would eliminate guesswork, researchers say
FRIDAY, April 9, 2010 (HealthDay News) -- Children would be better protected by seasonal flu vaccines if the vaccines contained both strains of influenza B instead of just one, the results of a new study suggest.
"Adding a second influenza B virus strain to the seasonal influenza vaccine would take some of the guesswork out of strain selection and help improve the vaccine's ability to prevent influenza," lead investigator Dr. Robert Belshe, director of the Center for Vaccine Development at Saint Louis University, said in a news release. "Since in five of the last 10 years, the influenza B component in the vaccine has been the incorrect one, this seems like an obvious advance to me."
He and his colleagues found that ferrets didn't have a strong antibody response when they were exposed to a strain of influenza B that didn't match what was in a single-strain vaccine. But the ferrets did show a strong antibody response when they received a vaccine with both strains of influenza B.
The researchers also looked at efficacy studies involving children and found that those who received an influenza vaccine that contained a strain of influenza B that matched what was circulating in the community were less likely to get the flu than children who received a vaccine that didn't match the circulating strain of influenza B.
The study, published in the March issue of the journal Vaccine, was sponsored by MedImmune, which makes a vaccine called FluMist. Belshe has served as a consultant and as part of the company's speakers bureau. The other study authors are MedImmune employees.
The U.S. Centers for Disease Control and Prevention has more about seasonal flu vaccine and children.