.
John Ross [MD] wrote:

In the past 2 years, one influenza strain (B/Yamagata) appears to have become extinct, and the rest are less genetically diverse. A welcome side effect of masking, social distancing, and improved hand hygiene.
CAVEAT: population immunity to influenza has probably declined in the past two years, and the “great demasking” could set us up for a big flu season. So get your flu shot and your COVID booster