Coronavirus may be in the headlines, but it’s still flu season, and a weird one at that — officials are seeing a new spike in flu activity as a second strain of flu hits on the heels of the first.
The 2019-2020 flu season already had an unusual start — in December and early January, the main strain of flu virus circulating was a type called influenza B, Live Science previously reported. Typically, influenza B does not cause as many cases as influenza A strains (H1N1 and H3N2) and tends to show up later in the flu season, not at the beginning. Indeed, the last time influenza B dominated flu activity in the U.S. was during the 1992-1993 flu season, according to the CDC.
But now, influenza A is making a comeback. In recent weeks, there has been a surge in activity of H1N1 in the U.S., according to data from the CDC.