We’re coming to you on Tuesday instead of our usual Thursday because something happened yesterday that couldn’t wait two days to cover.

Every week has brought new developments, new hearings, new appointments, and new announcements in the world of vaccine policy. Frankly, it has been a demoralizing year for those of us who work in public health, science communication, and clinical medicine. Yesterday was different. A federal court ruling in American Academy of Pediatrics v. Kennedy handed public health a significant, clear, and unambiguous win. It deserved its own edition. Let’s discuss…

The PDF version of today’s update is here. Read past installments here.

A Federal Judge Just Blocked RFK Jr.’s Vaccine Agenda

Yesterday, U.S. District Judge Brian Murphy issued a ruling that, in effect, temporarily blocks every major vaccine policy change made by President Trump’s administration over the past year. The ruling came in response to the ongoing lawsuit filed by the American Academy of Pediatrics (AAP) and five other major medical organizations against Health and Human Services (HHS) Secretary Robert F. Kennedy Jr.

The judge issued stays rather than a traditional injunction. This was likely a deliberate choice because it makes the overall ruling more difficult to challenge. The use of nationwide injunctions was limited in the Supreme Court’s 2025 ruling in Trump v. CASA, but under the Administrative Procedure Act, stays operate on a different legal footing. Critics of the ruling, including some ACIP members, argue that the distinction is purely cosmetic. Regardless, the practical effect is the same: everything the administration has done to vaccine policy since June 2025 is on hold—pending a full ruling on the merits of the case.

The judge opened his 45-page opinion with a quote from Carl Sagan’s The Demon-Haunted World: “Science is far from a perfect instrument of knowledge. History is littered with once-universal truths that have since come under scrutiny. Nevertheless, science is still the best we have.” Does anyone else have goosebumps?

Here is what the ruling does

The January 2026 memo that reduced the recommended childhood vaccine schedule from protecting against 17 diseases to only 11—issued without any involvement from the Advisory Committee on Immunization Practices (ACIP), public comment, or the evidence-based process that has governed vaccine recommendations for decades—is blocked. The recommendation against the hepatitis B birth dose has been overturned. The recommended childhood vaccine schedule reverts to its pre-January 2026 state.

Thirteen of the 15 current ACIP members are effectively sidelined (those appointed fromJune 2025 to January 2026). The 13 stayed members were appointed through a rushed, informal process that bypassed decades of established vetting. The two members added in late February 2026 were not evaluated by the court. Even under the most generous reading of their credentials, the court found only about 6 of 15 had meaningful vaccine-related expertise. The court specifically noted that several members, including a pharmacist, an OB/GYN, a psychiatrist, a pediatric cardiologist, and an emergency physician, had no documented vaccine-related expertise.

Every vote the ACIP committee has taken since June 2025 is effectively nullified, including the ban on thimerosal in flu vaccines, the downgrading of COVID-19 vaccine recommendations to shared clinical decision-making, the move away from the combined MMRV vaccine recommendation to separate MMR and varicella (chickenpox) vaccines, and the removal of the hepatitis B birth dose recommendation. The Evidence Collective documented at least 60 false, misleading, or unsupported claims made at the December 2025 ACIP meeting alone, a detailed record that informed both public understanding and the legal case.

The judge was clear about why he ruled the way he did. There is a method to how these decisions get made, one grounded in science and codified into law. Multiple federal statutes covering insurance coverage, Medicaid, veterans’ benefits, and the Vaccines for Children program explicitly tie their obligations to ACIP recommendations. The administration did not just cut corners; it broke the law.

One exchange from oral argument—included in the judge’s written opinion—captures how far the government’s legal position stretched. The judge asked whether, under the administration’s theory of unreviewable authority, the CDC could recommend that people go have lunch with someone who has measles instead of getting vaccinated. The government’s attorney said yes. The judge was unambiguous in his disagreement.

The ACIP meeting, which was previously scheduled for this week (March 18-19) is no longer happening—at least not in any official capacity. While the members can meet informally, they cannot operate as an official federal advisory committee or government resources and levers to shape vaccine access through insurance coverage or physician liability.

One additional nuance: the court did not explicitly stay the original May 2025 directive restricting COVID-19 vaccine recommendations for pregnant women and healthy children. However, the court found that the directive actually didn’t have any legal effect, either because it was superseded by the now-stayed January 2026 memo, or because it was never a final agency action to begin with. Practically speaking, the end result is the same.

What Does This Mean for Families and Clinicians Right Now?

The federal vaccine recommendations in place before June 2025 are back in effect for now. Routine childhood vaccines that had been previously downgraded or restricted regain their status as standard recommendations. Insurance coverage at no out-of-pocket cost remains in place because it is tied to ACIP recommendations under federal law, and major insurers had already committed to honoring the pre-change schedule through the end of 2026. There is also some relief here for clinicians, who had been concerned about civil liability from following scientific consensus rather than the now-stayed CDC recommendations.

For parents whose children may have missed or delayed vaccines during the months of policy uncertainty, it is worth talking to your pediatrician about whether any catch-up is needed.

What Comes Next?

This is a preliminary injunction—a temporary hold while the case moves through the courts. The administration has already signaled it will appeal. Expect this case to move to the First Circuit, and potentially beyond. There are also open questions about the ACIP’s reconstitution, and whether a lawfully constituted committee can be seated in time for fall vaccine decisions, which typically occurs in June.

For accessible explainers of the ruling,our friends at Your Local Epidemiologist and the Common Health Coalition both have breakdowns worth sharing.

What Was on the Agenda: The Leaked COVID-19 Vaccine Injury Report

The ACIP meeting this week was expected to focus heavily on COVID vaccine “injuries.” If you want the full picture of what that agenda looked like and why it raised red flags,the Evidence Collective’s prebunk brief covers it in depth.

The short version: on March 15, the New York Timesreported on a confidential ACIP work group document prepared for this week’s meeting. It proposed creating a new diagnostic category for post-COVID-19 vaccine injuries, termed PACVS or post-acute COVID-19 vaccination syndrome, along with new clinical guidelines and a network of research centers.

The document has significant problems. It cited a Rasmussen poll asking whether people personally know someone who died from a COVID-19 vaccine as evidence of widespread vaccine mortality. It relied primarily on case reports to claim a “consistent pattern” of immune dysfunction, a claim that describes individual patients but cannot establish causality. And it proposed actions that fall outside ACIP’s mandate entirely, including establishing ICD-10 diagnostic codes and clinical management guidelines, decisions that belong to other bodies within the federal health apparatus.

With this week’s meeting blocked, none of these votes will proceed for now. But the work group’s agenda has not gone away, and it will be worth watching what happens to this work if and when a reconstituted ACIP is seated.

People experiencing prolonged symptoms they attribute to COVID-19 vaccination deserve serious research and compassionate care. The concern here is with a process that starts from a conclusion and works backward, using evidence that does not hold up to scrutiny.

Personnel Chaos Continues

We covered some of the ongoing personnel chaos in our last issue, but it’s worth keeping an eye on. There has still been no movement on Casey Means, President Donald Trump’s nominee for surgeon general. As a reminder, the Senate HELP Committee needs to decide whether it will approve Means’ nomination. If her nomination is approved, it moves on to the full Senate. Currently, Republicans hold a one-seat majority on the committee. If all Democrats oppose, it takes only one Republican to vote no, and her nomination won’t advance. 

Senator Susan Collins from Maine and Senator Lisa Murkowski from Alaska have stated publicly that they are still on the fence. Senator Bill Cassidy of Louisiana chairs the committee. Even if you don’t live in one of these states, if your senator sits on the HELP Committee, you can contact their office. A list of committee members and their contact information is availablehere.

The CDC still lacks a permanent director. By law, a candidate needs to be nominated within 210 days of the vacancy opening, which is March 25th. 

On March 6th, Dr. Vinay Prasad, the director of the Center for Biologics Evaluation and Research at the FDA (the division responsible for approving vaccines and other biotech drugs), announced that he is resigning after a short tenure. Most recently, Prasad was in the news for rejecting and reversing course on the submission of Moderna’s experimental flu vaccine.

Measles: The Policy Consequences Are Already Here

As measles cases continue to climb across 31 states, the policy consequences of the environment that yesterday’s ruling just addressed are already visible. MMR coverage among kindergartners has dropped from 95.2% in 2019-20 to 92.5% in 2024-25, leaving an estimated 286,000 kindergartners unprotected. About 92% of confirmed 2026 measles cases are among people who were unvaccinated or had unknown vaccination status. 

The stakes of getting this wrong are not abstract. In February, the New England Journal of Medicinepublished a case report of a 7-year-old boy who had contracted measles as an infant and arrived at the Children’s Hospital of Orange County, California, with seizures and cognitive deterioration. He was diagnosed with SSPE — a rare but almost always fatal neurological complication that can appear years after a measles infection in someone who seemed to recover fully. Within a year of his first symptoms, he died. As measles spreads, more cases like his will follow.

Meanwhile, Governor Ron DeSantis, even as Florida manages a132-case outbreak across 13 counties, has signaled he will push vaccine exemption legislation through a special session after it failed during the regular session. The proposed bills would establish a conscience-based opt-out from school vaccine requirements — precisely the kind of policy that deepens the coverage gaps measles exploits.

Colorado Moves to Lock In Science-Based Vaccine Policy

Colorado is the latest state to proactively insulate its vaccine policy from federal disruption. The legislaturepassed Senate Bill 26-32 on Monday, allowing the state to rely on organizations like the AAP, the American Academy of Family Physicians (AAFP), and the American College of Obstetricians and Gynecologists (ACOG), rather than the federal CDC when establishing its childhood vaccine schedule. The bill also allows pharmacists to prescribe and administer vaccines, and creates no new mandates or exemption changes.

Colorado already has 11 measles cases this year, all in unvaccinated children, and is one of 29 states (plus Washington DC) that have explicitly rejected federal vaccine guidance. This bill codifies that position in state law. It passed the same day a federal judge blocked the federal schedule changes that Colorado was originally trying to insulate itself from. Regardless of what ultimately happens with the AAP v. Kennedy case, state-level protections still matter.

On Capitol Hill: Sanders Presses Cassidy on Vaccines and Autism

Senator Bernie Sanders sent a letter this morning to Senate HELP Committee Chairman Bill Cassidy demanding a hearing to set the record straight on vaccines and autism. Cassidy, a physician, has been publicly consistent that vaccines are “safe and effective and will not cause autism,” yet was the deciding vote to confirm Kennedy. Sanders is calling on him to put his vaccine statements on record formally, with a hearing featuring scientists, physicians, and public health experts.

The backdrop: Kennedy directed the CDC to alter a webpage that had previously stated “vaccines do not cause autism,” adding language suggesting health authorities had “ignored” possible links. The CDC kept the original statement but added an asterisk noting that it was there only because of a promise made to Cassidy. Cassidy faces a primary challenge in November from a Trump-endorsed candidate backed by a Kennedy-aligned political action committee. Whether he acts on this request will be worth watching.

Thanks to the Common Health Coalition’s Morning Vax View for flagging both the Colorado legislation and the Sanders-Cassidy story this morning.

Fall Flu Vaccine Strain Selection

On March 12, the FDA’s Vaccine and Related Biological Products Advisory Committee (VRBPAC)unanimously recommended the viral strains for next fall’s flu shots, the first such meeting since the Biden administration. Despite the U.S. having formally withdrawn from the World Health Organization (WHO) in January, U.S. scientists continued collaborating with international researchers on strain surveillance, and VRBPAC endorsed the WHO’s recommendations. All three strains are being swapped out, including subclade K, the dominant variant responsible for much of this season’s mismatch. The final decision rests with FDA Commissioner Martin Makary.

The timing matters because manufacturing flu vaccines takes approximately six months, so these decisions determine what will be available in clinics come fall. Amid a turbulent policy environment, the scientific process progressed on schedule and through established channels (that is not nothing). This season, at least101 children have died of influenza, roughly 85% of whom were unvaccinated. The number of flu vaccine doses distributed nationwide is down 23% from 2019-20, and it is these declining vaccination rates that have made a hard flu season even harder than it needed to be.

RSV Vaccine Expanded to At-Risk Adults Under 50

On March 13, the FDAexpanded the approved use of GSK’s RSV vaccine Arexvy to adults aged 18 to 49 at increased risk of lower respiratory tract disease. RSV, or respiratory syncytial virus, causes an estimated 17,000 hospitalizations, 277,000 emergency department visits, and nearly 2 million outpatient visits annually in this age group, primarily in people with underlying conditions including chronic cardiopulmonary disease, kidney disease, obesity, or diabetes. An estimated 21 million adults under 50 have at least one risk factor for severe RSV infection. The expansion was supported by phase 3b trial data showing a non-inferior immune response in younger adults compared to those 60 and older.

What to Watch

• The administration’s appeal of yesterday’s ruling will come. HHS has already signaled its intent to overturn the decision; watch for whether it heads to the First Circuit quickly or whether the government seeks to pause the stay while the appeal proceeds.
• ACIP’s future. With 13 of 15 members sidelined, the committee cannot function as intended. Whether the administration reconstitutes ACIP through proper procedure, pursues other avenues, or simply runs out the clock while appealing is an open question — one with real consequences for fall vaccine decisions, given the June deadline.
• Florida’s vaccine exemption push. DeSantis has signaled another run at this through a special session, in a state currently managing a measles outbreak across 13 counties.
• Other state-level legislation. Colorado’s bill is one example of a broader trend. Expect more states to codify their own vaccine schedules into law.
• The Cassidy hearing question. Sanders’s letter puts Cassidy on record. Whether the HELP Committee acts on it is a real variable in the months ahead.
• The fall vaccine season. Flu strain selection is done. RSV coverage just expanded. COVID-19 vaccine recommendations are in legal limbo. How all of this lands in practice for families, insurers, and clinicians is the story we will continue to track.

After a year of watching science get sidelined, processes get dismantled, and expertise readily dismissed, yesterday was a good day. It’s by no means the end of the fight, but it’s a very good start. We are going to keep making sense of it all together. Our next installment will be in two weeks, on Thursday as usual; we’ll see you then.