The Food and Drug Administration blocked the publication of studies that tracked the safety of the COVID-19 and shingles vaccines, an official told ABC News.
U.S. regulators approved updated COVID-19 shots Wednesday but limited their use for many Americans - and removed one of the two vaccines available for young children.
The American Academy of Pediatrics said on Tuesday that children ages 6 months to 23 months should receive a COVID-19 vaccine, in contrast with federal health officials.
Some patients report a sharp, stabbing pain when they swallow, often at the back of the throat.
Updated guidance on the CDC website appears to be walking back some of the changes for healthy children and pregnant women that RFK announced earlier this week.
These changes, made in unconventional ways, will probably affect access to and availability of COVID-19 vaccine shots for millions.