Donald Trump signed an executive order Monday directing federal health agencies to revise childhood vaccination recommendations, a move that promotes his long-standing view that routine shots should be spread across more medical visits.
The order recommends administering the measles, mumps and rubella (MMR vaccine) as three separate injections on different days. It also instructs the Department of Health and Human Services to expand vaccine safety research. A White House fact sheet says the administration will urge states to align school-entry requirements with the new guidance, though vaccination mandates remain a state responsibility.
Public health experts warned that spacing out doses leaves children vulnerable to infection during the gaps between visits. The separate measles, mumps and rubella vaccines the order envisions are not currently produced for the U.S. market. The Centers for Disease Control and Prevention's existing schedule, which combines the three components in a single shot given at 12 to 15 months, is based on decades of safety and efficacy data.
Autism claims persist despite evidence
Trump has repeatedly linked vaccines to autism, a connection that large-scale studies across multiple countries have conclusively ruled out. In a cabinet meeting last month he pressed Robert F. Kennedy Jr., the health secretary, for progress on autism research Kennedy had promised to deliver. Scientific bodies including the World Health Organization and the Public Health Agency of Canada maintain there is no credible evidence of a causal relationship.
The order arrives as the United States contends with a measles resurgence. Cases have approached 1,000 in the first weeks of 2026, most of them in unvaccinated children. The outbreak threatens the country's measles elimination status, a designation Canada also holds and monitors closely given cross-border travel.
Canadian context
Canada sets its own immunization schedule through the National Advisory Committee on Immunization (NACI), which recommends the combined MMR vaccine at 12 months with a second dose at 18 months or before school entry. Provinces and territories fund and deliver the programs. Canadian measles cases have also risen in recent years, driven by pandemic-related delays and vaccine hesitancy, but coverage remains higher than in many U.S. jurisdictions.
Health Canada notes that single-antigen measles, mumps and rubella vaccines are not authorized for sale in Canada. Any shift in U.S. policy that reduces combination vaccine use could complicate supply chains for manufacturers that serve both markets.
Polling shows most Americans still support school vaccine requirements, though a partisan gap has widened. The executive order does not carry the force of law and will likely face legal challenges similar to those that blocked a previous HHS attempt to cut the number of recommended childhood vaccines.
Based on reporting by Global News.