The CDC will study the potential link between vaccines and autism, sources have revealed.
Two sources told Reuters the agency is planning a large study into the long disproven connection.
It is unclear whether newly appointed health secretary Robert F Kennedy Jr, who has long been skeptical of vaccines, is involved in the planned study or how it would be carried out.
The CDC and the Department of Health and Human Services (HHS) could not immediately be reached for comment.
The bombshell move comes amid one of the largest measles outbreaks in US history, with more than 150 cases across the country and two deaths in Texas and New Mexico.
Experts believe the outbreak has been fueled by declining vaccination rates in parts of the US.
Kennedy, whose role includes authority over the CDC, has long sowed doubt over the safety of the measles, mumps and rubella (MMR) vaccine, along with Covid shots made by Pfizer and Moderna.
However, he did make a U-turn move earlier this week when he urged people to get the shot to prevent measles.