WASHINGTON — President Donald Trump has signed an executive order directing federal health officials to pursue changes to the nation's childhood vaccination schedule, creating a significant new debate over U.S. public-health policy.

The order calls for a schedule featuring 11 immunizations, which the administration says would provide strong protection while reducing the number of childhood vaccinations.

The administration is also seeking consideration of separating the measles, mumps and rubella (MMR) vaccine rather than continuing to administer it as a combined shot.

The announcement could have major implications for pediatricians, parents, vaccine manufacturers and public-health agencies.

Supporters of the changes argue that the vaccination schedule should be reassessed and made more flexible. Public-health experts, meanwhile, are expected to closely examine whether changes could affect vaccination coverage and protection against preventable diseases.

The order comes as vaccination policy remains a politically sensitive issue in the United States.

The administration's move now places America's childhood immunization schedule at the center of a major national healthcare debate, with medical organizations and families likely to closely watch how federal recommendations evolve.