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Flu vaccine effectiveness questioned

December 05, 2014

Early data suggests that the current 2014-2015 flu season could be severe.

The Centers for Disease Control and Prevention (CDC) urges immediate vaccination for anyone still unvaccinated this season – unless their doctor recommends against it because of a life-threatening allergy to the flu vaccine or any of its ingredients. The agency recommends prompt treatment with antiviral drugs for people at high risk of complications who develop flu.

flu vaccine effectiveness

If that isn’t enough, in a warning issued to doctors Wednesday night, the CDC informed them that only 48 percent of flu virus samples taken through last month were closely related to this year’s North American vaccine.

What does that mean? The flu vaccine may not be as effective as it has been in previous years.

It offers protection against three to four strains of flu, such as H3N2, which is currently infecting most people, and has mutated. As a result, only about half of cases match the vaccine.

worth it

Dr. Daniel Skiest, chief, Infectious Disease Division at Baystate Medical Center, said you shouldn’t use this as an excuse to not get vaccinated.

"Sometimes the vaccine is not a perfect match, but there is still value in getting the flu vaccine, which will provide some protection," Dr. Skiest said. "Also, it’s still early in the season to know exactly what the match will be, as other strains covered by the vaccine could become more prevalent."

Dr. Skiest noted getting a flu shot is especially important for the young and old, who are most at risk for serious side effects from the flu, which can cause death. 

Seniors age 65 and older have the option to choose a newer flu vaccine with a higher dose. The high dose vaccine is associated with a stronger immune response to vaccination (higher antibody production).