President Donald Trump’s administration is slated to lay out its approach to Covid vaccination at an event Tuesday that could spell major changes in what is required to get regulatory approval for immunizations.

The vaccine will only be available to those at high risk from COVID—excluding those who may need it to protect a relative or friend.

After a six-week delay, the US Food and Drug Administration has approved Novavax’s Covid-19 vaccine, according to a letter from the agency, but only for people 65 and older and those 12 and up who have at least one underlying condition that puts them at higher risk of severe illness.