FDA panel backs subclade K as centerpiece of fall flu shots

U.S. FDA vaccine advisers unanimously endorsed including the A(H3N2) subclade K in next fall’s flu vaccines, aligning with WHO guidance; final approval rests with FDA Commissioner Makary. Subclade K has become the dominant strain in the Northern Hemisphere, highlighting the annual, uncertain process of strain selection. The season saw limited vaccine effectiveness and a high pediatric burden, with falling vaccination rates since the pandemic, alongside tens of millions of illnesses and thousands of hospitalizations.