The legal fight over the federal government's decision to drop a universal hepatitis B vaccine dose at birth is widening. Vermont joined a multistate lawsuit this month, bringing the coalition to 16 state attorneys general plus Pennsylvania's governor, after the states filed an amended complaint on Oct. 2, according to the Vermont attorney general's office.

The case arrives alongside new evidence. A study published Oct. 19 in Annals of Internal Medicine projected that moving the first dose from birth to a family decision could raise chronic hepatitis B infections in children by 83% by age 20, according to a release from the American College of Physicians. Under that scenario, more than half of children could enter adulthood without protection.

For parents of newborns, the practical question is simpler than the legal one. Because a federal court has paused the change, the CDC's website still says all infants should receive the hepatitis B vaccine, ABC News reported. The American Academy of Pediatrics continues to recommend a first dose within 24 hours of birth.

Two Court Fights, One Policy

In December 2025, the Advisory Committee on Immunization Practices voted to end the universal birth-dose recommendation in place since 1991. The CDC then adopted shared clinical decision-making for babies whose mothers test negative, meaning parents and providers decide together whether to give the dose at birth or start no earlier than 2 months, according to the Department of Health and Human Services.

A January 2026 CDC memo went further, removing the universal recommendation for seven childhood vaccines, including hepatitis B. The states argue in federal court in Northern California that these changes violate the Administrative Procedure Act and that Health Secretary Robert F. Kennedy Jr.'s replacement of all 17 voting committee members in June 2025 was unlawful. Vermont Attorney General Charity Clark said the changes "run afoul of decades of scientific evidence."

A separate case brought by the American Academy of Pediatrics produced the ruling now in effect. On March 16, U.S. District Judge Brian Murphy in Massachusetts stayed the January memo, the new committee appointments and the committee's votes, including the hepatitis B decision. The Justice Department appealed on April 29, STAT reported, and the U.S. Court of Appeals for the First Circuit heard arguments on Oct. 6. As of Oct. 29, no appellate ruling had been reported.

The Administration's Case for Choice

HHS has defended the change as a matter of informed consent for low-risk families. Babies born to mothers who test positive or whose status is unknown are still recommended to receive the birth dose with immunoglobulin. When the policy was adopted, then-acting CDC Director Jim O'Neill said those newborns whose mothers test negative "face little risk of contracting hepatitis B."

Asked about the new study, HHS pointed ABC News to a post by Kennedy. "I reject the idea that respecting parents' choices means abandoning children's health," he wrote. HHS has also said insurance coverage for the vaccine remains in place across federal programs, including Vaccines for Children and Medicaid.

What the Model Projects

Researchers at Massachusetts General Hospital and Harvard Medical School followed a simulated birth cohort of 3.6 million U.S. infants through age 20. They compared three approaches for babies of mothers who test negative: a universal birth dose, a first dose delayed to 2 months, and shared decision-making for that first dose.

Delaying the first dose raised projected chronic infections by 19%, while shared decision-making raised them by 83%. The number of children still vulnerable to infection at age 20 rose from about 232,000 under the universal birth dose to about 1.8 million under shared decision-making, according to ABC News. If high-risk babies were also vaccinated less reliably, infections passed from mother to child could double or triple.

Corresponding author Dr. Amir Mohareb, an infectious-disease physician at Mass General Brigham, said the team aimed to add evidence to a debate already playing out in courts and professional societies. He called for restoring the universal birth-dose recommendation.

Limits of a Projection

The study is a peer-reviewed computer model, not a count of real infections. Its results depend on assumptions about vaccine uptake, maternal screening, exposure in households and missed follow-up doses, and the release did not report absolute numbers of new chronic infections. It also modeled a single year of births, so the authors' warning that effects would add up over many years is an extrapolation.

What is not in dispute is the stakes of infection — and how early they begin. Most babies infected at birth or in infancy develop lifelong chronic hepatitis B, which has no cure and raises the risk of liver cirrhosis and liver cancer decades later. The vaccine is up to 90% effective at preventing mother-to-child infection when given within 24 hours of birth, the Vermont Attorney General's Office noted.

For expectant parents, the most useful step now is to ask about prenatal hepatitis B testing and discuss the birth dose with their obstetrician or pediatrician before delivery. Families who skipped the birth dose can ask their pediatrician about starting the series. The hepatitis B vaccine remains covered for children through Vaccines for Children and most insurance plans.

The First Circuit ruling is the next major event, and it will decide whether the March stay remains in place while the cases continue. The bottom line is that the universal birth dose is still the recommendation in effect today — but its future depends on appeals judges, and new modeling suggests the policy choice could shape liver health for millions of children decades from now.

What Readers Want to Know

Is the hepatitis B birth dose still recommended?

Yes, for now. A March 16 federal court order paused the change, and the CDC's website still says all infants should receive the vaccine.

What did the CDC change?

It moved the birth dose to shared clinical decision-making for babies whose mothers test negative, with a first dose no earlier than 2 months if the birth dose is skipped.

Who is suing?

A coalition of 16 state attorneys general and Pennsylvania's governor in federal court in Northern California, and the American Academy of Pediatrics in Massachusetts.

What did the new study find?

A model of 3.6 million infants projected 19% more chronic infections by age 20 with a delayed first dose and 83% more with shared decision-making.

What does HHS say?

HHS says the change respects parental choice for low-risk newborns and that insurance coverage for the vaccine continues.

What should expectant parents do?

Ask about prenatal hepatitis B testing and discuss the birth dose with your obstetrician or pediatrician before delivery.

What happens next?

The First Circuit, which heard arguments Oct. 6, will decide whether the court-ordered pause stays in place.