Flu Shots Need to Stop Fighting ‘Something That Doesn’t Exist’

In Arnold Monto’s ideal vision of this fall, the United States’ flu vaccines would be slated for some serious change—booting a major ingredient that they’ve consistently included since 2013. The component isn’t dangerous. And it made sense to use before. But to include it again now, Monto, an epidemiologist and a flu expert at the University of Michigan, told me, would mean vaccinating people “against something that doesn’t exist.”

That probably nonexistent something is Yamagata, a lineage of influenza B viruses that , shortly after COVID mitigations sent flu transmission plummeting to record lows. “And it isn’t for lack of looking,” Kanta Subbarao, the director of the WHO’s Collaborating Centre for Reference and influenza B virus samples collected from February to August of last year. Not a single one of them came up Yamagata. “The consensus is that it’s gone,” Cheryl Cohen, the head of South Africa’s Centre for Respiratory Diseases and Meningitis, told me. Officially removing an ingredient from flu vaccines will codify that sentiment, effectively publishing Yamagata’s obituary.