Trump's childhood vaccine order will threaten children's safety, even if it doesn't directly change policy

President Donald Trump's recent executive order on childhood vaccines has generated a predictable and understandable debate around public health needs, parental autonomy and the scientific justifications for the directive. The order proposes, among other things, altering the U.S. childhood vaccine schedule and splitting up the combined MMR vaccine into multiple shots. As an immunologist, my view is that the order contradicts established scientific consensus and instead backs narratives that are not supported by evidence.

However, the more important issue with the order may be something more fundamental: What happens when vaccine policy is divorced from the scientific processes designed to guide it?

For many decades, the U.S. relied on a transparent process in which scientists, physicians, public health experts and vaccine specialists reviewed evidence and developed recommendations for who should receive a given vaccine and when. Through this process, there would be disagreements, which is not only expected but welcomed. Constructive debate on policy can lead to the development of better policies. But replacing expert scientific review with political directives risks creating a precedent that extends well beyond vaccines.

Dr. Avery August is the 2026-2027 President of the American Association of Immunologists, as well as an HHMI professor, deputy provost, and professor in the Department of Microbiology and Immunology at Cornell University. His previous position was as distinguished professor of immunology in the Department of Veterinary & Biomedical Sciences and director of the Center for Molecular Immunology & Infectious Disease at The Pennsylvania State University at University Park, where he started as an assistant professor. He received a B.S. degree in medical technology from the California State University at Los Angeles, and a Ph.D. in immunology from the Weill Cornell Graduate School of Medical Sciences.

It's very possible that the immediate impact of the executive order will be limited. Many pediatricians, state public health agencies and professional medical organizations are likely to continue following established immunization schedules that were developed through decades of scientific review and real-world experience. The order itself does not magically change how vaccines work, how doctors practice medicine, or how states set school vaccination requirements.

Indeed, while the order says a lot, it doesn't hold direct authority to change vaccine recommendations. These, at least for now, are still protected by federal laws. The order can set direction but not policy.

Nevertheless, it would be a mistake to conclude that the order does not matter, because the true risk it poses is that it creates confusion and uncertainty for parents and caregivers, who only want to protect their children as best they can.

Vaccination programs rely on something fragile: the public's confidence. This confidence can be destroyed easily. Parents deserve to have trustworthy information when making decisions about the health of their children. Physicians, too, must trust that vaccine schedules reflect the best available science. Weakening those foundations of trust will further contribute to declining vaccination rates, even if no formal mandates change.