The FDA approved the first mRNA flu vaccine

Moderna's mFlusiva cleared for adults 50-64 with 27% fewer test-confirmed infections than a standard-dose shot, and accelerated approval in 65+.

The FDA approved Moderna's mFlusiva on August 5, the first influenza vaccine ever licensed using messenger RNA. It carries a standard approval for adults aged 50 to 64 and an accelerated approval for adults 65 and over. In the 50-64 group, trial participants who received it were 27% less likely to contract test-confirmed influenza than recipients of a standard-dose vaccine. The mRNA arm reported substantially more side effects, most of them mild and lasting one to two days.

The part that matters beyond this one product is manufacturing time. Egg-based and cell-based flu vaccines require the strain selection to be locked months ahead of the season, which is why a mismatched year is a bad year. mRNA production is fast enough that the strain choice can be made closer to the season, so the same platform that is approved today is also a shorter, cheaper production line tomorrow. Moderna says it expects some doses available ahead of the coming flu season.

The caveats are real and they are about evidence, not safety. An accelerated approval in the over-65s means the confirmatory evidence is still owed. The 27% figure is relative to standard-dose comparators, not to the high-dose and adjuvanted vaccines that older adults are often given. And no dose volume, list price or contract price has been published, so the platform's cost advantage remains an argument rather than a number on a curve.

Source: STAT