As the Trump administration rolls out a revised childhood vaccine framework, Colorado’s law allowing the state to set its own immunization schedule has now taken effect.

Issued Monday, President Donald Trump’s executive order separates childhood and adolescent vaccines into three categories: those recommended for all children, certain high-risk groups and “based on shared clinical decision-making.”

The order also calls for administering the measles, mumps and rubella or MMR, vaccine in three separate doses and for administering all childhood vaccines at separate medical visits.

A section of the order also calls for Health and Human Services Secretary Robert F. Kennedy Jr. to present a plan to the president to “improve vaccine research and options for American parents.”

During the signing, Trump suggested that the number or timing of vaccines could play a role in rising rates of autism among American children. Critics of the changes maintained that the scientific consensus and decades of studies have concluded there is no link.

Trump has questioned whether the MMR vaccine should be given as a combined shot, a White House spokesperson said, adding that the executive order is intended to give parents “more options on timing and frequency” for their children.

“For long — and far too long — a long period of time, America has recommended more childhood vaccines than any peer nation and even twice as many doses as some European countries and even more than that,” Trump said on Monday.

His executive order also said a scientific assessment found that, instead of “implementing vaccination mandates, most peer nations maintain high childhood vaccination rates through public trust and education. In the United States, by contrast, individual States set mandatory vaccination requirements that children must meet to attend school.”

Last year, following vaccine scheduling changes implemented by the Centers for Disease Control and Prevention under Kennedy, the Colorado General Assembly passed legislation allowing the State Board of Health to establish its own vaccine schedules. The measure also allows medical professionals to follow recommendations from the American Academy of Pediatrics and other entities, rather than those issued by the federal government.

The bill, which went into effect on Aug. 12, also updates liability provisions for vaccines required for school entry, allowing compliance with either the Centers for Disease Control and Prevention immunization schedule or the schedule established by the State Board of Health.

“Relying on science-based immunization information to keep our communities safe shouldn’t be controversial, yet the Trump administration continues to unravel healthcare tools trusted by doctors and public health experts,” said bill sponsor Rep. Kyle Brown, D-Louisville. “This bill builds upon our work to safeguard immunization access in Colorado and ensure it’s backed by trusted organizations that follow the science. Regardless of the misinformation touted by Washington and Secretary Kennedy, this bill prioritizes science-driven information to protect the health and safety of Coloradans.” 

Colorado is among 15 states suing the Trump administration over changes to the childhood vaccine schedule. The lawsuit, filed in February, argues that the revised guidelines endanger public health and will force states to spend more to prevent outbreaks.

In a statement, Attorney General Phil Weiser said Kennedy and the CDC “disregarded federal law, ignored scientific evidence, and put our children in danger by gutting recommended childhood vaccines.”

Colorado Politics sought comment from the State Board of Health but did not receive a response.

Colorado Politics reporter Marianne Goodland and Ali Swenson and Collin Binkley of The Associated Press contributed to this story.