President Donald Trump signed an executive order on Monday directing sweeping changes to the childhood vaccination schedule, recommending that shots be administered in separate visits and that the combined measles, mumps and rubella (MMR) vaccine be broken into three individual injections.
The order instructs the nation’s health department to revise vaccine recommendations and expand research into immunization safety. It marks an effort to bypass the authority of the U.S. Centers for Disease Control and Prevention (CDC), the federal agency historically tasked with setting vaccine guidance rather than the White House.
The move builds on earlier attempts this year to reshape the childhood shot schedule, changes that were previously halted by a federal judge. It also aligns with the priorities of Health and Human Services Secretary Robert F. Kennedy Jr., a longtime vaccine skeptic.
A central provision calls for separating the MMR vaccine into three distinct shots. However, standalone measles, mumps and rubella vaccines are not currently available in the United States, and administering them separately is more costly than the combined dose.
Trump has for years suggested that the number or timing of childhood vaccines could contribute to autism spectrum disorder. Decades of scientific studies and broad medical consensus have firmly established that no such link exists.
Childhood vaccines and their combinations undergo rigorous clinical testing before approval, with safety monitoring continuing for years after the shots enter widespread use.
Public health experts have warned that spacing out immunizations across multiple visits raises the risk that children could contract a vaccine-preventable disease during the intervals before returning for subsequent doses.
The order arrives as the school year begins across the country and as the United States contends with a measles outbreak that specialists say could cost the nation its measles elimination status. A White House fact sheet outlining the changes framed the policy as an expansion of parental choice and improved research.
The directive extends a broader pattern of executive action on health policy under the current administration, following earlier orders on domestic pharmaceutical manufacturing and drug imports. It also follows recent shifts in federal immunization guidance that weakened Covid and childhood recommendations.
Because the CDC, not the White House, holds statutory authority over vaccine recommendations, the order is expected to face legal scrutiny. Medical organizations and public health officials are likely to challenge the changes in court, setting up a further test of executive power over federal health agencies.