Public health advocates have largely applauded a Massachusetts judge’s ruling on March 16, 2026, to temporarily block major changes to vaccine policy made by the Department of Health and Human Services since 2025.

The ruling pauses two major actions ushered in by HHS Secretary Robert F. Kennedy Jr. since he stepped into the role. First, it blocks Kennedy’s restructuring of a key vaccine panel called the Advisory Committee on Immunization Practices in June 2025. Second, it suspends HHS’s overhaul of the childhood vaccine schedule in January 2026, which cut the number of routine vaccinations children are recommended to receive from 17 to 11.

As an epidemiologist who studies vaccine hesitancy and a public-facing science communicator, I view these HHS actions as extremely damaging to public health, and I am relieved they have been paused, at least while legal proceedings are ongoing.

However, I also worry that this back-and-forth is detrimental to trust in science, especially for families who are already uneasy about vaccinating their kids or feel hesitant to do so.

What exactly happened?

The March 16 decision follows a lawsuit originally brought in July 2025 by six medical organizations, including the American Academy of Pediatrics. The medical organizations argued that HHS’s changes were implemented without following established legal and scientific processes.

The ruling seems to align with that view, concluding that the government’s overhaul of the vaccine committee likely “fails to comport with governing law” and that its changes to the vaccine schedule were “arbitrary and capricious.”

The judge’s action suggests that the court believes the plaintiffs are likely to succeed in showing that the HHS changes violated federal law.

The ruling returns recommendations on the childhood vaccine schedule – made by the Centers for Disease Control and Prevention, one of HHS’s primary divisions – to their pre–June 2025 status while the case proceeds. It also blocks HHS’s replacement of members of the Advisory Committee on Immunization Practices, which reviews evidence and develops recommendations that guide vaccine-related decisions by the Centers for Disease Control and Prevention.

The ruling effectively pauses the vaccine committee’s work. The members appointed by Kennedy cannot serve at the moment, and the previous members do not automatically return, leaving the committee inactive for now.

Officials from HHS have indicated that they are likely to appeal the ruling.

Does the ruling change people’s ability to access vaccines?

Not at the moment, because right now nothing has changed about what vaccines children should receive. Pediatricians should be following the long-standing vaccine schedule as it existed before the HHS’s change in June 2025. Most physicians already are, having followed the American Academy of Pediatrics’ decision not to back HHS’s revised schedule.

Additionally, private insurers as well as federal health programs such as Medicaid, the Children’s Health Insurance Program and Vaccines for Children had already agreed to continue covering all the vaccines through 2026, even before the judge intervened.

From a health economics perspective, data shows that the downstream costs of treating vaccine-preventable illnesses are much higher than the cost of reimbursing vaccines, so insurance companies may be motivated to continue covering them.

Moving forward, however, the ongoing court case could affect vaccine availability because many insurance companies and public programs rely on recommendations from the Advisory Committee on Immunization Practices to determine which vaccines are covered or provided at no cost.

If your children are behind on any vaccines, it would be a good idea to get them now, given the uncertainty.

What effect might the ruling have longer term?

It’s important to remember that even though policy shifts in vaccine recommendations can be confusing, the data on the safety and efficacy of childhood vaccines has not changed. There were no safety alerts or new clinical trials that precipitated HHS’s change to the vaccine schedule.

Even with the prior recommendations back in place, however, all the back-and-forth in the headlines may create confusion for parents. Mistrust of vaccines and public health is at an all-time high, fueled by disinformation, poor communication on the part of public health agencies, and other factors that arose mostly during the COVID-19 pandemic.

Parents have long considered health agencies such as the CDC to be trustworthy but increasingly look upon them with skepticism. A survey in January 2026 showed public trust in federal health agencies has declined following HHS’s changes to the childhood vaccine schedule.

Immunization rates, meanwhile, are on the decline, particularly for measles. An analysis released by Reuters on March 18, 2026, of vaccination data from Michigan suggests the number of toddlers receiving routine vaccines fell sharply from January 2025 to January 2026, and that Kennedy’s attack on vaccines influenced parents’ decisions to forgo them.

Rebuilding trust in vaccines and public health will take time and will require consistent, transparent communication and strong engagement between clinicians and families. The court ruling potentially represents an initial step in that process.

For parents with questions about vaccines, the best source of information remains their child’s pediatrician. Parents can also look to evidence-based vaccine schedules maintained by health groups such as the American Academy of Pediatrics.

Katrine L. Wallace does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.