On December 16, 2025, the Centers for Disease Control and Prevention (CDC) made a move that stunned much of the medical and public health community: it dropped its long-standing recommendation for universal hepatitis B vaccination at birth. This decision, the first major change to the U.S. childhood immunization schedule since its inception in 1995, was made under the leadership of Health and Human Services Secretary Robert F. Kennedy Jr., a figure whose skepticism about vaccines has long been a flashpoint in American health policy debates.
For decades, the U.S. childhood immunization schedule has stood as a bulwark against diseases that once claimed the lives of thousands of children each year. Built gradually since the mid-20th century, the schedule was shaped by outbreaks, scientific breakthroughs, and the hard lessons of public health failures. The CDC, guided by its Advisory Committee on Immunization Practices (ACIP), has added vaccines only after rigorous trials and continuous safety monitoring, ensuring that each addition was both effective and necessary. The hepatitis B vaccine, introduced for newborns in 1991, was one such measure. Before its addition, about 18,000 children annually contracted hepatitis B before their tenth birthday, a virus that is especially dangerous for infants, with a 90% risk of chronic infection and a 25% chance of developing cirrhosis or liver cancer.
According to CNN, the hepatitis B birth dose served as a crucial safety net, protecting infants from infection acquired not just from their mothers during birth, but also from other household contacts. The universal approach was adopted because targeted strategies failed—too many mothers slipped through the cracks of screening, and the virus’s ability to survive on surfaces for days made household transmission a constant threat. The results were dramatic: hepatitis B infections in American children plummeted by 99% after the vaccine’s adoption.
Yet, despite this success and decades of evidence supporting the vaccine’s safety, the CDC’s new stance now frames hepatitis B vaccination at birth as an “individual” decision. This reversal, as The Guardian reports, came without new evidence questioning the vaccine’s safety or efficacy. Instead, the change reflects a broader overhaul planned by Kennedy, who has announced intentions to further align the U.S. vaccine schedule with that of Denmark—a country with far lower hepatitis B prevalence, universal health care, and a robust national patient registry.
These developments have not gone unnoticed, nor unchallenged. Major medical organizations, including the American Academy of Pediatrics and the American College of Obstetricians and Gynecologists, have publicly rejected the CDC’s reversal. Several states—California, New York, and Illinois among them—have signaled they will continue to follow established, evidence-based guidelines, regardless of federal recommendations. Their rationale is clear: the U.S. health care system, fragmented and often inaccessible for millions, cannot reliably replicate the targeted, registry-based approach that works in Denmark.
The changes at the CDC have been swift and, to many, alarming. In June 2025, Kennedy dismissed all 17 members of ACIP, replacing them with his own appointees—many of whom have a history of anti-vaccine views. This new panel has pushed for policies that critics say are out of step with decades of scientific consensus and public health best practices. According to STAT, William Thompson, a CDC vaccine adviser with ties to Kennedy, has been promoted to oversee research into adverse childhood experiences and will help shape the agency’s Youth Risk Behavior Surveillance System, the largest public health surveillance system monitoring high school students’ health behaviors. Thompson, who previously suggested the CDC omitted data on vaccine risks, is now tasked with aligning research with Kennedy’s “Make America Healthy Again” movement, raising concerns about the direction of federal health research.
The ripple effects of these policy shifts are being felt far beyond U.S. borders. On December 19, 2025, The Guardian reported that the Trump administration would fund a $1.6 million study on hepatitis B vaccination of newborns in Guinea-Bissau, a West African nation where nearly one in five adults is infected with the virus. The study, to be conducted by Danish researchers Peter Aaby and Christine Stabell Benn, will randomly assign some infants to receive the hepatitis B vaccine at birth and others to wait, despite the World Health Organization’s recommendation that all babies receive the vaccine at birth. Experts have condemned the study as unethical and risky, arguing that withholding a proven intervention in a high-risk population is a major breach of scientific ethics.
Paul Offit, director of the Vaccine Education Center at Children’s Hospital of Philadelphia, told The Guardian: “He has a fixed, immutable belief that vaccines cause harm. He will do everything he can to try and prove that.” Elizabeth Jacobs, professor emerita at the University of Arizona, added, “It is spreading like an infection all its own throughout the globe.” Gavin Yamey, professor of global health at Duke University, called the study “highly unethical” and “extremely risky,” noting that there is already robust evidence that the hepatitis B vaccine at birth saves lives. “Why on Earth is this study happening in a high-endemic setting where the birth dose matters the most?” Yamey asked.
The study’s design has raised further concerns. It is single-blinded, meaning the researchers—not the participants—know who received the vaccine, potentially introducing bias. Its endpoints, described as “overall health effects,” are vague and susceptible to manipulation, said Henrik Støvring, a professor of statistics at Aarhus University. “Broad hypotheses like these carry a high risk of false positive findings, and in general the research group has previously been reluctant to use appropriate statistical methods to curb such a risk,” he warned.
Meanwhile, Kennedy’s decision to end U.S. funding to Gavi, the Vaccine Alliance—which has vaccinated over 1.2 billion children worldwide—has sent shock waves through the global health community. Kennedy justified this move by citing a controversial 2018 Danish study that claimed the DTP vaccine increased mortality in girls in Guinea-Bissau, though a subsequent 2022 paper from the same group found no such effect. Critics say Kennedy’s selective use of data and willingness to fund ethically questionable research threaten to undermine trust in vaccines and public health institutions worldwide.
Despite the growing number of recommended vaccines in the U.S., advances in technology have reduced the number of immune-stimulating antigens children receive—from about 3,000 in the 1980s to fewer than 160 today. Yet, the debate over vaccine policy has never been more contentious or consequential. As Offit put it, “This breaks my heart. It really does. It’s hard to sleep knowing that children are constantly being put in harm’s way by the administration.”
The coming months will test the resilience of America’s public health infrastructure, as states, medical organizations, and global partners grapple with the consequences of a federal retreat from evidence-based vaccine policy. The stakes could hardly be higher for children in the U.S. and around the world.
