A Surprise Flu Variant Threw Off the Vaccine. Get Ready for a Brutal Winter

Scientists are sounding the alarm: this winter’s upcoming flu season in North America could be a real nightmare, thanks to the rapid arrival of a variant that doesn’t match well with the seasonal flu vaccine.

Health officials in Canada issued the warning in a paper late last month. An unexpected variant of the H3N2 flu, dubbed subclade K, quickly emerged during the tail end of the flu season in the Southern Hemisphere this year, they noted. Subclade K is now poised to become one of…