How do scientists pick what goes into each year's flu shot?
Short answer: A global network watches flu all year, experts meet every February, and the FDA makes the final U.S. call. Here's how each year's flu vaccine is chosen. So the flu shot is an educated guess, built from worldwide surveillance and updated every year.
Full transcript
Hook
Why and how do scientists pick what goes into each year's flu shot? It changes every year, and the decision is made months before flu season starts.
Change
Flu viruses mutate constantly. The version going around this winter can be different from last year's, so last year's vaccine might not match.
Network
So labs around the world watch flu all year. More than a hundred fifty national flu centers in over a hundred twenty countries send samples to a global World Health Organization network.
Meeting
Twice a year, experts meet to study the data. In February, they recommend which viruses to include for the Northern Hemisphere's next flu season.
Fda
In the United States, an FDA advisory committee reviews the evidence and makes the final pick for American vaccines.
Three
Current U.S. flu shots cover three viruses, two flu A strains and one flu B strain.
Bet
It's a prediction, made months ahead so manufacturers have time to make enough doses. Some years the match is great, other years it's weaker.
Close
So the flu shot is an educated guess, built from worldwide surveillance and updated every year. ThatsWhyHow.
Sources
- CDC
- Selecting Viruses for the Seasonal Influenza Vaccine
Spotted an error? Leave a comment on the video. Corrections are pinned and noted here.