The FDA approved the first mRNA flu vaccine for use in older adults. Here’s what to know

Key Points:

• The FDA has approved the first mRNA-based flu vaccine, mFlusiva by Moderna, for use in adults 50 and older, marking a significant advancement by leveraging technology used in Covid-19 vaccines.
• Unlike traditional flu vaccines that use inactivated virus strains selected months in advance, the mRNA vaccine allows for later strain selection and faster manufacturing, potentially improving strain matching and effectiveness.
• Moderna received standard approval for ages 50-64 and accelerated approval for those 65 and older, with the latter contingent on further post-marketing studies to confirm clinical benefits over enhanced flu vaccines currently recommended for seniors.
• The mRNA flu vaccine showed about 27% greater effectiveness than standard shots in trials but had higher rates of mostly mild to moderate side effects; serious adverse events were rare and comparable to traditional vaccines.
• Availability this fall may be limited due to early vaccine ordering practices, and insurance coverage remains uncertain pending CDC advisory committee recommendations, which have been delayed due to recent federal legal challenges.