President Donald Trump issued an executive order late last week that further muddies an already unclear picture for the US childhood vaccine schedule.

The executive order, accompanied by a fact sheet from the White House, directs the Centers for Disease Control and Prevention (CDC) and its Advisory Committee on Immunization Practices (ACIP) to review a December 2025 scientific assessment from the Department of Health and Human Services (HHS) that called for fewer recommended childhood vaccines and to take “any appropriate steps” to update the US childhood vaccine schedule to align with its findings. 

“The scientific assessment, with its proposed updates to the categories of the vaccine schedule, is acknowledged as a guiding resource for the Federal Government,” the executive order states.  

The HHS assessment called for paring the number of recommended vaccines for US children from 17 to 11 after a review found that the United States recommends more childhood vaccines than “peer nations” like Denmark. In early January, then-acting CDC director Jim O’Neill signed a memorandum saying the agency would adopt the recommendations. 

The changes were widely criticized by public health groups, including the American Academy of Pediatrics (AAP). The AAP has maintained its recommended childhood vaccine schedule, and at least 23 states and Washington, DC, have said they will follow those recommendations rather those issued by the CDC. 

In March, a federal judge in Boston ruled that the changes to the childhood vaccine schedule adopted by the CDC didn’t follow proper administrative procedures. HHS has not appealed that ruling, which came in response to a lawsuit filed by the AAP and other leading medical groups. 

ACIP status is unclear 

Because of that ruling, the federal childhood immunization recommendations that were in place before June 2025 remain in place. For now, the immediate effect of the executive order is rhetorical, said Jess Steier, DrPH, a public health and science communicator and founder and CEO of Unbiased Science. 

That’s because the ruling by US District Court Judge Brian E. Murphy temporarily blocked the ACIP, whose membership has been overhauled by HHS Secretary Robert F. Kennedy Jr, from meeting. 

The judge concluded that several of the 13 new members tapped by Kennedy to serve on ACIP had no vaccine-related expertise and were not qualified under the group’s original charter. All decisions made by the group, including a controversial recommendation to delay the first dose of the hepatitis B shot in infants if the mother has tested negative for the virus, were nullified.

A March meeting of ACIP was subsequently postponed. Although HHS has issued a revised charter that would expand the group’s membership criteria, it’s unclear when ACIP—which would have to approve the HHS vaccine recommendations before the CDC can sign off on them—will meet next.

“The EO [executive order] has no operational teeth right now,” Steier said in an email.

Still, opponents of the Trump administration’s vaccine policies say they’re concerned. 

“This is the second time the administration has attempted to unilaterally substitute vaccine guidance from other countries to replace the U.S. vaccine schedule which was developed for the specific needs of the U.S. population,” American College of Physicians President Jan K. Carney, MD, MPH, said in a statement. “The changes that this order directs cannot be allowed to move forward.”

Steier said the question is whether the order is simply meant to appease supporters of Kennedy’s Make America Healthy Again movement after a series of losses on vaccines or serve as “groundwork for redoing the January schedule changes in a way that survives judicial review.”

“The bigger concern is what it sets up, not what it does today,” she said.