Subclade K flu gets an early start in Japan, could affect U.S.
The Subclade K flu variant is spreading rapidly in Japan, Canada and the United Kingdom and could affect those who have not received their annual flu shots in the United States ahead of the 2025 holiday season. File Photo by Huntlh/Pixabay
A new flu variant called Subclade K is spreading in Japan and poses a significant risk to the United States as cold and flu season arrives this winter.
The flu variant is a new version of the type A flu virus that commonly spreads at the traditional start of the flu season and is followed by the type B virus at the season’s end, according to The Japan Times.
The variant has caused a spike in flu cases in Japan, Canada and the United Kingdom, and already is taking root in the United States.
Officials with the Japan Institute of Health determined 22 of 23 patient samples analyzed since September were positive for the Subclade K flu variant, Nippon.com reported.
That’s a 96% positive rate, but the variant does not pose a greater risk of producing severe flu symptoms and is not significantly more contagious than any other flu variant, according to the JIHS.
The health ministry reported 196,895 flu cases have been noted at about 3,800 medical facilities through Nov. 23, for an average of more than 51 flu patients at each facility.
The average is well above the amount needed, 30 per facility, to trigger a national flu warning, which has been issued in Japan.
The amount also greatly exceeds the average of 2.36 flu patients per facility a year ago.
The early start to the flu season partly is attributed to the Subclade K variant arriving at the same time that most Japanese citizens obtain flu vaccinations.
The early arrival means many were afflicted before they could get their respective flu shots and lacked the antibodies needed to fight off the affliction.
The flu season in Japan peaked at the end of last year with an average of 64.39 patients.