Flu Vaccine Mismatch
This year’s flu vaccine may not adequately protect recipients from the currently circulating strains of influenza. While we remain in the early stages of the 2014-2015 flu season, over 90 percent of the 1,200 samples submitted to The Centers for Disease Control and Prevention (CDC) have been the H3N2 subtype of influenza A, half of which are genetically drifted strains against which this season’s flu vaccine offers poor protection.
“Unfortunately, about half of the H3N2 viruses that we’ve analyzed this season are different from the H3N2 virus that’s included in this year’s flu vaccine. They’re different enough that we’re concerned that protection from H3N2 viruses may be lower than we usually see,” noted Thomas Frieden, Director of the CDC, in a recent CDC Telebrief.
An advisory released by the CDC last week stated 52 percent of the influenza virus samples analyzed from October 1 through November 22 were different than the strains of the virus included in this year’s vaccine, which could mean a season with more hospitalizations and more deaths than most.
While the strain mismatches will lead to lower overall efficacy this season, the CDC still recommends getting a flu shot.
“Vaccination has been found to provide some protection against drifted viruses in past seasons,” said Joseph Bresee, Head of the CDC’s Influenza Department. “Also, vaccination will offer protection against other flu viruses that may become common later in the season.”
The CDC has also urged doctors to bypass waiting for confirmation of the flu and immediately prescribe antiviral drugs like Tamiflu to high-risk patients displaying flu-like symptoms.