Older adults and other groups at high risk for severe illness might still be able to get vaccinated, the FDA vaccine chief said Tuesday.

The Food and Drug Administration is planning major changes for how Covid vaccines are rolled out and who will be able to get the updated shots this fall.

In a paper published Tuesday in the New England Journal of Medicine, FDA Commissioner Dr. Marty Makary and Dr. Vinay Prasad, the FDA’s new vaccine chief, wrote that any new Covid vaccine now must undergo placebo-controlled clinical trials — meaning, some people would get the actual vaccine while others get an inactive substance like a saline shot, to compare results.

At a planned FDA vaccine panel meeting on Thursday, agency advisor are expected to advise the vaccine makers which strains to target for new shots. The new clinical trial requirement isn’t expected to affect the fall rollout for older adults and other people at high risk for severe illness because drugmakers are exempt from additional testing for those groups.