President Trump is escalating his administration's controversial overhaul of the U.S. childhood vaccine schedule, announcing plans to demand that certain childhood shots be split into five separate doses administered at six-month intervals — without providing any scientific evidence for the move. Trump claims this will dramatically reduce autism rates, a theory that has been thoroughly debunked by decades of research involving millions of children worldwide.

This latest announcement builds on an August 2026 executive order that cut the federally recommended childhood immunization schedule from 17 to 11 vaccines, directed the Justice Department to challenge state school vaccination laws, and called for splitting the MMR vaccine into three separate shots — a feat experts say could take a decade, since no licensed single-antigen measles, mumps, or rubella vaccines currently exist in the U.S. Courts had previously blocked a similar January 2026 schedule overhaul pushed by HHS Secretary Robert F. Kennedy Jr., finding officials had acted unlawfully.

Key Takeaways:

• Major medical groups — including the AAP, AMA, and IDSA — unanimously reject the changes, citing no new scientific evidence and warning of increased parental confusion and vaccine hesitancy
• More than 40 well-designed studies involving millions of children have found no link between vaccines and autism
• Splitting combination vaccines across more visits risks delayed or missed immunizations, potentially exposing children to preventable diseases
• The MMR split is currently unfeasible — no licensed standalone measles, mumps, or rubella vaccines exist in the U.S.

Why it matters: These policy shifts, driven by political priorities rather than scientific evidence, threaten to erode decades of public health progress. With measles cases already at a 35-year high, experts warn that reduced vaccination rates could trigger broader outbreaks of diseases once considered eliminated.