Flu virus tracker: Latest update shows high influenza activity across most states. Watch out for these symptoms
Influenza A H3N2 subclade K is driving a nationwide surge in flu cases, with high positivity rates, substantial hospitalizations, and pediatric deaths.
An H3N2 subclade-K with modest immune escape caused an earlier, somewhat stronger flu season, but transmission and severity remain within expected ranges.
A nasty 'superflu' virus is spreading in the U.S. right now: What to know about the subclade K flu variant
A mutated H3N2 subclade K is driving increased influenza cases, pushing U.S. respiratory visits above the epidemic threshold during the northern winter.