A 3-D print of an influenza virus, showing the surface antigens hemagglutinin (blue) and neuraminidase (red)FLICKR, NIAID
While widespread vaccination is still the best defense against the influenza virus, the US Centers for Disease Control and Prevention (CDC) warned last week (December 4) that many of this year’s circulating strains are different from the ones used to formulate the annual flu vaccine.
So far this season, more than 90 percent of the reported flu cases in the US are of the H3N2 subtype, and 52 percent of the samples tested have mutations in antigen-encoding genes compared to the sample used to produce the annual vaccine.
“They’re different enough that we’re concerned that protection from vaccination against the drifted H3N2 viruses may be lower than we usually see,” CDC Director Thomas Frieden said. “These changes can signal that the immune response provided by ...
