But the framework has perhaps created as much confusion as clarity. Broadly, the FDA said it will limit approval of Covid-19 vaccines to people 65 and older and to those at risk for severe Covid outcomes, and will require vaccine makers to conduct clinical trials investigating whether the shots benefit healthy adults and children.

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.”

The US Food and Drug Administration is changing the way it approves Covid-19 vaccines for Americans — a move that will limit future vaccines to older Americans and people at higher risk of serious Covid-19 infection.