Flu shot less effective this year because current virus has mutated
(CNN) — Scientists are concerned about what they’re seeing so far this flu season, the director of the Centers for Disease Control and Prevention said Thursday, a day after the agency advised doctors this year’s flu vaccine is not as effective because the current strain of the virus has mutated.
Dr. Tom Frieden said researchers are worried that with this particular strain of the virus, “we could have a season that is more severe than most with more hospitalizations and more deaths.”
The advisory sent Wednesday said 52% of the 85 influenza virus samples collected and analyzed from October 1 through November 22 were different than the virus strains included in this year’s vaccine, indicating a mutation, or drift, of the strain.
The most common strain of the virus reported so far this season is influenza A (H3N2). In the past, this strain has been linked to higher rates of hospitalization and death, especially for those at high risk for complications, which is usually the very young, the elderly and those with chronic health conditions such as asthma or heart problems.