Vaccine effectiveness in South America against hospitalization was reported at 34.5% this year, a drop from last year's 51.9%, indicating potential lower protection in the U.S.
The decline in flu vaccine effectiveness may be linked to a shift towards H3N2 strain dominance this year, contrasting last year’s H1N1 dominance which typically received better vaccine responses.
Data from a research network indicated that previously, flu vaccine effectiveness was estimated at around 43% for fully vaccinated young children and 41% for older adults, highlighting variations in success rates.
Given the Southern Hemisphere's flu trends, U.S. health authorities may predict similar lower protection levels this coming winter season, mirroring South America's recent vaccine performance.
Collection
[
|
...
]