The Food and Drug Administration says it has decided to continue approving COVID-19 vaccine updates for seniors and others at higher risk of severe disease, but will require vaccine makers to conduct major new clinical trials before approving them for wider use.

For groups younger than 65 or without specific chronic conditions, postmarketing trials will be needed to open access.

The change marks a shift in the Food and Drug Administration’s policy on approving COVID-19 vaccines, which the new commissioner described as a “one-size-fits-all regulatory framework.”