What you should know about the new mRNA flu vaccine

The FDA’s approval of an mRNA flu shot presents a new, long-awaited option—and raises big questions about the future of flu vaccines.

On August 5, the US Food and Drug Administration approved Moderna’s mFLUSIVA, the first influenza vaccine to use mRNA technology, for adults 50 and older.

The approval gives many older Americans a long-awaited new option for protection. Tens of thousands of Americans typically die from the flu every year,...