
US flu vaccine underperforms against new strain, officials say
CDC data show this season’s flu vaccine was about 25%–30% effective at preventing illness requiring medical care for adults and roughly 40% for vaccinated children, due mainly to a newly dominant H3N2 subclade not well matched by the vaccine. An estimated 27 million illnesses, 350,000 hospitalizations and 22,000 deaths have occurred; adult vaccination is about 46.5% and around 48% of kids have been vaccinated. Vaccination remains worthwhile to reduce severe illness, and next season’s vaccines will be updated to address the subclade.













