For 10 years, Americans have had access to flu shots that protect against four strains of the virus: two A strains and two B strains. Starting this fall, however, all the flu shots distributed in the United States will probably contain only three strains, and the change is because of Covid-19. A Yamagata strain was typically included in each year’s flu shot recipe, so vaccine designers faced a quandary: Should they drop the strain from the formula or keep it in, since B-viruses are known to be cagey? It’s not quick or easy to change how flu vaccines are manufactured, and those changes require regulatory review and approval. The committee is meeting Tuesday to discuss next steps and vote on flu vaccine recommendations for the fall.

Source: CNN March 05, 2024 18:15 UTC