Main Flu Strain Has Mutated; Current Flu Vaccines May Not Prevent Infection
It's bad news for the vaccine, said Scott Hensley, a professor of microbiology at the University of Pennsylvania who led the study. Flu vaccines protect against four strains: H3N2, H1N1 and two strains of influenza B. The study covers just H3N2, but that happens to be the main circulating strain.
Flu Vaccines Don't Match The Main Circulating Flu Virus Strain, Researchers Find
One of the main circulating influenza viruses has changed and the current flu vaccines don't match it well any more -- an indication they may not do much to prevent infection, researchers reported Thursday. But they are still likely to prevent severe illness. "From our lab-based studies it looks like a major mismatch," Scott Hensley, a professor of microbiology at the University of Pennsylvania who led the study, told CNN. It's bad news for the vaccine, he said. Influenza vaccines protect against four different strains of the flu: H3N2, H1N1 and two strains of influenza B. Hensley's study only covers H3N2, but that happens to be the main circulating strain. (Fox, 12/16)
The CDC's chart of past flu vaccines shows a so-so history of effectiveness:
Past Seasons' Vaccine Effectiveness Estimates
In the 2019-20 flu season, the adjusted overall effectiveness of the flu vaccine was just 39%. In the past 16 flu seasons listed on the CDC chart, the adjusted overall vaccine effectiveness has been as high as 60% and as low as 10%. (12/17)
In related news about the flu —
After a year with almost no flu in Wisconsin, it's back — and fewer people are getting the shot
Tom Haupt, the state's influenza surveillance coordinator, told USA TODAY NETWORK-Wisconsin the surge in flu cases, especially among college students, has been "remarkable." He pointed to an early November outbreak at the University of Michigan, where over 300 cases were diagnosed in a single week, prompting the Centers for Disease Control and Prevention to investigate. Wisconsin's flu vaccination rate, which has never topped 50%, is also lower this time than last year, according to the surveillance report. (Heim, 12/16)
Very Well Health:
When Should You Get Tested For The Flu?
Peter Chin-Hong, MD, professor of infectious diseases at University of California, San Francisco, recommends taking a flu test if you tested negative for COVID-19. While uncommon, it’s possible to be infected with both COVID-19 and flu at the same time. “I think a lot of people are stuck in limbo land with symptoms,” Chin-Hong told Verywell. “You keep doing a million BinaxNOW assays just because you want to convince yourself that you don't have COVID.” (Bugos, 12/14)