The University of Southern Denmark approved a controversial study in Guinea-Bissau that withholds hepatitis B birth-dose vaccines from half of enrolled newborns, backed by $1.6 million from the CDC, while new research warns that narrowing similar U.S. vaccination policies could spike infections and leave millions vulnerable.
University Approval and International Condemnation in Guinea-Bissau
The University of Southern Denmark confirmed that it has given the green light to a controversial study in Guinea-Bissau, a developing nation where nearly one in five people carry the hepatitis B virus. Chronic infections kill 15% to 25% of those infected by causing liver failure or cancer, making birth-dose vaccination a critical preventative tool. Yet the clinical trial plans to administer the life-saving vaccine to only half of the 14,000 newborns enrolled in the study.
News of the project first surfaced in December, triggering an immediate international outcry from political leaders and health advocacy groups who challenged its safety design. That pressure forced Guinea-Bissau officials and Danish administrators to halt the research for months. However, the project gained new momentum when university dean Professor Jakob Grauslund, PhD, MD, approved the protocol following an an independent ethical assessment
conducted by the school’s research ethics committee.
No child enrolled in the study will receive fewer vaccines than under current national policy in Guinea-Bissau.
Bandim Health Project, via University of Southern Denmark source reporting
The Bandim Health Project, led by Danish researchers Peter Aaby, PhD, and Christine Stabell Benn, MD, PhD, defended the decision by noting that Guinea-Bissau does not currently vaccinate newborns at birth, a practice the World Health Organization recommends but which the country does not plan to adopt nationally until 2028. While the revised protocol received local ethical clearance over the summer, Grauslund noted that Final governmental authorization in Guinea-Bissau has, however, not yet been granted, and the study cannot begin until the necessary national authorization has been obtained.
Advocacy group condemns trial as human rights violation
Opposition to the trial remains fierce. Stand Up for Science, a nonprofit advocacy group, condemned the initiative as a gross violation of human rights and the use of bad science against some of the most vulnerable people in the world,
according to founder and CEO Colette Delawalla, PhD, who added that the organization is exploring all possible actions at its disposal to prevent this study from happening.
Meanwhile, Wessam Mankoula, MD, a medical epidemiologist and acting director of the Africa CDC’s Center of Public Health Emergency, acknowledged at a press conference that discussions were ongoing between the U.S. and Guinea-Bissau governments.
The international dispute unfolds alongside domestic policy battles over newborn immunization schedules in the United States. Robert F. Kennedy Jr., serving as Secretary of Health and Human Services, recommended ending the decades-old practice of administering the hepatitis B birth dose to all newborns. In June 2025, Kennedy replaced all 17 members of the Advisory Committee on Immunization Practices with figures sharing his vaccine skepticism. Although a federal judge temporarily blocked the resulting proposals in March, the underlying legal battle continues to threaten universal birth-dose guidelines.
Harvard study shows risks of delaying birth vaccines
To evaluate the real-world stakes of altering these guidelines, infectious-disease researchers at Massachusetts General Hospital and Harvard Medical School modeled potential outcomes for 3.6 million children born in a single year across the United States. Led by Dr. Amir Mohareb, the study published in the Annals of Internal Medicine assessed what would happen if universal birth doses were replaced with delayed vaccination or shared clinical decision-making.
- Delaying the first vaccine dose from birth to 2 months of age increases chronic infections acquired by age 20 by 19%, rising from 255 annual cases to 303.
- Shifting to a shared decision-making model drives chronic infections up by 83% to an average of 467 cases annually.
- A shared decision-making policy leaves more than 50% of children born each year entering adulthood susceptible to the virus.
- Two separate studies published in JAMA Pediatrics in April found that delaying the dose adds $16.4 million in medical costs and requires screening hundreds of thousands more pregnant women to prevent infections.
Overturning a long-standing immunization practice warranted evidence, and so that was the motivation to study this,
Mohareb explained. Dr. José Romero, who led the ACIP from June 2018 to August 2021, criticized the current advisory panel for failing to consult modeling data before recommending policy rollbacks, asserting that such evidence would have stopped them from endorsing a change.
Frequently Asked Questions About the Hepatitis B Vaccine Debate
Why is the hepatitis B vaccine traditionally administered at birth?
Doctors give the first vaccine dose within 24 hours of birth to protect infants from known transmission risks and to serve as a vital safety net when maternal infection status is unknown, medical records are inaccurate, or exposure happens later through household contacts.
What status does the Guinea-Bissau clinical trial currently hold?
While the University of Southern Denmark approved the protocol following an independent ethical review, final governmental authorization in Guinea-Bissau remains pending, meaning the study cannot start until national officials grant final clearance.
How do proposed U.S. changes affect newborn protection?
Proposed policy shifts would replace universal birth-dose recommendations with a targeted approach or shared decision-making for infants born to mothers testing negative for the virus, potentially leaving millions of children vulnerable to chronic infection over time.