KarunaNews Story

Amid travel restrictions, quarantines, closures, physical distancing, masking, enhanced hand washing, and disinfection, the 2020-2021 flu season was all but canceled. Many subtypes of the virus all but vanished. One entire lineage -- one of only four flu groups targeted by seasonal influenza vaccines -- has not been definitively detected since April 2020. What the absence of this B/Yamagata lineage might mean for future flu seasons and flu shots is an open question. Fewer flu viruses could make it easier to match future vaccines to circulating viruses, but a surprise re-emergence of B/Yamagata could become more dangerous as time passes and people lose immunity. The researchers urge flu surveillance laboratories to increase efforts to detect any Yamagata cases to determine if it's truly gone or just lying low.