Trump pushes separate MMR shots, staggered vaccinations as US measles outbreak worsens

US President Donald Trump has signed an executive order seeking a major overhaul of the country’s childhood immunisation schedule, including plans to separate the combined measles, mumps and rubella (MMR) vaccine into three individual shots.

The order also calls for childhood vaccinations to be spread across separate medical visits rather than administering several vaccines during a single appointment.

The move comes as the United States faces its worst measles outbreak in decades, with more than 2,300 cases reported so far this year, according to official figures. The number has surpassed the total recorded in 2025 and represents the country’s highest annual measles caseload since 1991.

Trump calls for separate vaccine visits

Speaking during the signing ceremony at the White House, Trump said children should receive vaccines across multiple appointments rather than receiving several shots during one visit.

He gave the example of a child receiving vaccines at age one and said families should potentially make several separate visits instead of having all recommended shots administered on the same day.

The executive order directs the Department of Health and Human Services (HHS), headed by Robert F Kennedy Jr, to examine changes to the national childhood immunisation schedule.

One of its key provisions calls for plans to make separate vaccines available for measles, mumps and rubella instead of relying on the combined MMR shot.

The order also seeks to reorganise childhood vaccines into different categories, including core recommendations, vaccines for people at higher risk and those subject to shared decision-making between doctors and families.

Push to change state vaccine rules

The order also seeks to influence vaccination requirements imposed by individual states.

States have authority over many school vaccination requirements, meaning the federal government cannot directly impose a nationwide school-entry mandate.

The administration is instead urging states to review their vaccination requirements in line with the revised federal recommendations.

The order also directs the Justice Department to examine state policies relating to religious and medical exemptions from vaccination requirements.

Medical groups oppose changes

The move has drawn strong criticism from doctors and public health experts, who argue that separating vaccines and requiring additional appointments could make it harder for children to receive timely protection.

Medical organisations have also questioned the scientific basis for breaking up the MMR vaccine.

The combined MMR shot has been used for decades, with extensive evidence supporting its safety and effectiveness. Public health experts say administering multiple vaccines during the same appointment reduces the number of visits families need to make and helps ensure children are protected on schedule.

Dr Andrew Racine, president of the American Academy of Pediatrics, told CNN that the scientific evidence supporting vaccines had not changed and warned that spreading vaccinations across multiple appointments could create unnecessary barriers.

Standalone MMR shots face practical hurdles

The proposed separation of the MMR vaccine could also face immediate logistical difficulties.

Standalone measles, mumps and rubella vaccines are not currently available as routine products in the United States in the form envisioned by the order. Developing and licensing separate vaccines would therefore require additional regulatory and manufacturing steps.

Doctors have warned that the changes cannot simply be implemented overnight in paediatric clinics.

The American Academy of Pediatrics has also estimated that developing approved standalone vaccines could take years.

Lawmakers raise concerns

The order has faced criticism from lawmakers, including some Republicans.

Senator Bill Cassidy, a physician and chairman of the Senate Health Committee, criticised the move and questioned Trump’s authority to determine changes to the country’s vaccination policy.

Cassidy said vaccines are safe and effective and argued that the president does not have the medical expertise required to make such changes.

The criticism is particularly significant because Cassidy previously supported Kennedy’s controversial appointment as HHS secretary.

US measles outbreak raises alarm

The policy shift comes as measles continues to spread across the United States.

The country formally achieved measles elimination status in 2000, but declining vaccination coverage has raised concerns that sustained transmission could threaten that status.

Health officials say measles spreads rapidly when vaccination levels fall below the threshold needed to maintain community protection.

The national MMR vaccination rate has declined in recent years, while non-medical exemptions have increased in some areas.

Public health experts fear that adding more appointments and changing a long-established vaccination schedule could make it harder for parents to keep children fully immunised.

The administration, however, argues that the executive order is needed to reconsider the current approach to childhood vaccination and give families and doctors greater flexibility in deciding how vaccines are administered.