Two studies released on Monday predict that a new U.S. policy recommending the hepatitis B vaccine at birth only for babies deemed at risk of neonatal infection could lead to a rise in infected infants and chronic hepatitis B cases in children, resulting in millions in additional healthcare costs.
“Avoiding an increase in neonatal infections under the targeted recommendation would require historically unattained levels of maternal [hepatitis B] screening or birth-dose coverage among infants of unscreened mothers,” said one of the studies conducted by researchers from Boston University, the University of Florida, and Johns Hopkins University.
The second study, conducted by researchers at Oregon Health and Science University, the Los Angeles County Department of Public Health, Emory University, and Cornell University, projected that postponing the first dose of the hepatitis B vaccine to two months for babies born to mothers who tested negative for the virus could lead to an additional 90 infections, 76 chronic infections, and 29 hepatitis B-related deaths each year, with over $16 million in extra healthcare costs for each annual birth cohort.
The first study estimated annual infections could vary from 69, if 80% of the babies recommended for a birth dose received it, to 628 if only 10% were vaccinated.
Published in JAMA Pediatrics, these studies employ mathematical modeling to evaluate the effects of the contentious new policy, which was approved by the Advisory Committee on Immunization Practices in early December and adopted by the Centers for Disease Control and Prevention soon after, despite objections from public health experts.
Hepatitis B is a highly infectious virus spread through bodily fluids. While a vaccine exists to prevent infection, there is no cure. Most adults who contract the virus can clear it, but infants have a 90% risk of developing chronic hepatitis B, with about 25% of those cases leading to premature death from liver disease.
The ACIP, with members appointed by health secretary Robert F. Kennedy Jr., voted to change a long-standing recommendation for universal hepatitis B vaccination at birth, suggesting instead that only babies born to mothers who have tested positive or have not been screened should receive the vaccine immediately. Parents of babies born to mothers who tested negative during pregnancy are given the option to delay vaccination until the child is two months old.
Many states have expressed their intention not to implement this recommendation, and its status remains uncertain. In mid-March, a federal court judge issued a preliminary ruling in a legal case challenging the restructuring of the ACIP and associated vaccination policy changes. Judge Brian E. Murphy indicated these actions were likely illegal.
Arthur Reingold, a professor of infectious disease epidemiology at the UC Berkeley School of Public Health, noted that previous ACIP versions would have thoroughly reviewed research like these studies before altering the hepatitis B birth dose recommendation. However, he observed that there is no evidence the current ACIP did so.
Reingold, who has served on the ACIP, strongly opposes the new policy, stating, “The fact of the matter is … the hepatitis B birth dose has been given to tens of millions of children in the United States and hundreds of millions around the world. And there’s simply not a shred of evidence that there are any adverse effects or safety concerns.”
In an accompanying editorial, Grace Lee, a former chair of the ACIP, highlighted that the debate over the policy change did not adequately consider the potential harms of changing the recommendation, focusing instead on hypothetical risks of vaccination.
Lee pointed out that the studies’ estimates of the policy’s impact were conservative. They did not account for the possibility that altering the policy could reduce parents’ willingness to vaccinate their infants against hepatitis B, complicating the program’s implementation for hospitals and pediatricians.
“As health systems and health care professionals are keenly aware, implementation is not about intent, it is about friction,” wrote Lee, associate dean for maternal and child health at Stanford University School of Medicine. “With enough friction, it becomes easier to not vaccinate than to vaccinate.”
The widespread implementation of the new recommendation remains uncertain. Organizations like the American Academy of Pediatrics and the American College of Obstetrics and Gynecologists, which have traditionally aligned with ACIP guidelines, no longer match their vaccination recommendations with the CDC’s.
Concerns persist that the new recommendation could cause confusion and decrease the number of infants vaccinated against hepatitis B.
Noele Nelson, senior author of the second study, stated in an email, “Lack of a universal birth dose recommendation weakens provider and parent confidence and disrupts long-standing protocols for universal birth dose administration which could cause unscreened mothers and their infants to fall through the cracks.”
Nelson, a public health professor at Cornell University, added, “Unscreened mothers may lack prenatal care, lack insurance, and have other health barriers causing them to be unscreened which contribute to lack of optimal neonatal care.”
Rachel Epstein, senior author of the first study, concurred. “We know in general in medicine — infectious diseases in particular — that an intervention is more effective if it’s recommended for everyone,” said Epstein, a pediatric and adult infectious disease physician and clinician investigator at Boston Medical Center. “This could be a situation where having to look for the risk and not it being a routine thing might make the vaccination rate lower in those babies.”
Epstein and her colleagues referenced data from 1999 to support their argument.
The universal birth dose recommendation, initiated in 1991, significantly reduced infant hepatitis B cases. However, in 1999, the AAP suggested pausing the birth dose for babies born to mothers who tested negative due to concerns about the vaccine preservative thimerosal. Subsequent studies have refuted claims linking thimerosal to increased autism rates.
During the pause, the vaccination rate for babies of unscreened mothers dropped from 53% to 7%, despite unchanged recommendations to offer the vaccine to these infants. The rate improved once the universal birth dose recommendation resumed.
Currently, about 86% of pregnant individuals are tested for hepatitis B. The new ACIP policy advises that babies of untested mothers should still receive a birth dose, but based on past experiences, Epstein and her co-authors warn that even slight reductions in coverage could significantly raise neonatal infection rates.
Lee’s editorial noted that even before the policy change, the percentage of babies receiving hepatitis B birth doses was declining, falling to 73.2% last August from 83.5% in February 2023.
