Panel members had questions about whether a new FDA proposal to require randomized trials for vaccines in healthy adults might delay manufacture and limit access.

In calling for more clinical testing of vaccines in younger people and those who face a low risk of severe disease from Covid-19, the FDA said its policy will compel generation of more evidence for these groups.

If coronavirus vaccines are restricted to seniors and those at high risk, parents of young children and relatives of medically vulnerable people face a higher bar for shots.

Previously, updated COVID vaccines had been recommended annually by the CDC for everyone over the age of 6 months. The CDC has historically set vaccine recommendations, while the FDA determines which vaccines to authorize or approve after being deemed safe and effective.

The FDA is requiring COVID vaccine makers Pfizer and Moderna to update their warnings about the possible risk of myocarditis and pericarditis.

The FDA picked the LP.8.1 Covid strain for the fall vaccines, fueling concerns that the shots may be limited to only the most at-risk Americans this fall.

A group of experts who advise the US Food and Drug Administration on its vaccine decisions voted unanimously Thursday to make a broad recommendation about which lineage of the coronavirus should be included in this year’s Covid-19 vaccines,

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.