President Donald Trump signed an executive order this month to reduce the federal childhood immunization schedule from 17 to 11 shots. The order also directs the Department of Health and Human Services (HHS) to separate the combined measles, mumps, and rubella (MMR) vaccine into three individual injections and instructs the Justice Department to challenge state-level school vaccination requirements. Five current and former administration officials told Reuters the order was driven by the president's concern that current policies do not sufficiently address what he considers a potential link between vaccines and autism.
The move follows a period of internal activity led by Health Secretary Robert F. Kennedy Jr., who took office in early 2025 promising to investigate the causes of rising autism rates. In January 2026, Kennedy introduced a revised immunization schedule that bypassed typical regulatory processes, but a federal judge blocked those changes in March 2026, ruling that health regulators had acted unlawfully. The administration is currently appealing that decision while moving forward with dozens of new studies using federal health datasets to examine vaccine safety and chronic disease.
Administration officials stated the executive order was "quickly cobbled together" following a July 31 cabinet meeting where President Trump publicly questioned Kennedy regarding the progress of autism research. While the administration describes the order as a response to parents' ignored concerns, medical groups have expressed concern that the changes will increase vaccine hesitancy and expose children to preventable illnesses. Pharmaceutical companies have noted that the directive to split the MMR vaccine into separate shots could take years to implement.
The day-to-day impact on households will involve a different logistical approach to pediatric care. If the MMR vaccine is successfully split, children would require three separate appointments and injections rather than a single visit, a process experts say could take up to a decade to fully realize due to manufacturing and regulatory requirements. Medical groups suggest this change may lead to increased confusion during routine check-ups and potentially higher out-of-pocket costs or time commitments for caregivers managing multiple vaccination schedules.
The policy sets a precedent for executive intervention in the established scientific processes used by agencies like the Centers for Disease Control and Prevention (CDC). By directing the Justice Department to litigate state-level requirements, the administration is challenging the traditional authority of states to set their own public health standards for schools. The ongoing research studies at HHS are expected to continue for months or years, while the administration’s appeal of the March 2026 court ruling will determine if the health secretary can permanently reshape vaccine policy without further legislative or judicial hurdles.