In brief
Guinea‑Bissau recently halted a US‑funded hepatitis B vaccine trial that faced ethical criticism for withholding life‑saving shots from some newborns. The experiment, led by a Danish research team, was paused after a judicial police raid and ongoing investigations. Stakeholders now question the trial’s compliance with national safety standards and the wider impact on African scientific research.
Guinea‑Bissau has stopped a controversial United States‑funded hepatitis B virus vaccine trial that would have withheld life‑saving shots from half the babies enrolled, after a judicial police raid seized vaccine batches and an ongoing inquiry into the study’s compliance with the country’s safety standards. The findings were reported on 30 August 2026 and followed a series of events that began with the trial’s announcement in December last year, which sparked widespread condemnation from public health experts and the general public alike.
The study, originally designed by the Bandim Health Project—a Danish research group based in Bissau and affiliated with the University of Southern Denmark—aimed to compare the effect of the World Health Organization–recommended hepatitis B (HBV) birth‑dose schedule with a six‑week‑dose schedule. Researchers planned to enroll approximately 14,000 babies, dividing them at random into two groups—one receiving the vaccine at birth and the other waiting until six weeks of age—and follow the children for five years to assess health outcomes.
Funding for the project came from the U.S. Centers for Disease Control and Prevention, with a grant of $1.6 million secured under Health Secretary Robert F. Kennedy, who has previously expressed anti‑vaccine views. The trial’s design—testing a vaccine that, according to the lead investigators, could contain inactivated viruses—was seen by many as ethically problematic because it would withhold a WHO‑recommended, life‑saving intervention from a sizeable portion of the study population.
“This is a significant setback for African science,” said one researcher involved in the project in a public statement.
“This is a significant setback.”
Following the announcement, the Guinea‑Bissau government paused the project in January, initiating a review of the trial’s ethical and regulatory compliance. Local health officials and international observers expressed deep concern that the study failed to adhere to national guidelines and international standards concerning infant vaccination protocols. There was no official comment from the government in the weeks after the initial pause.
In mid‑October, Guinea‑Bissau’s judicial police raided the Bandim Health Project’s facilities in the capital, Bissau, and confiscated vaccine batches. Police officials said investigations were underway to determine whether the trial had complied with the country’s safety standards. The raid sparked intensified debate about the treatment of experimental research projects in a country with limited oversight infrastructure.
Background on the investigators shows that Christine Stabell Benn and her husband, Peter Aaby, have led the Bandim Health Project since 1978. Their research focuses on unintended vaccine impacts, and they have posited that vaccines containing inactivated viruses can cause death—an assertion that has drawn criticism from other scientists. Meanwhile, their Danish counterparts have repeatedly accused the University of Southern Denmark affiliates of down‑playing the study’s potential harms.
Under the International Council for Harmonisation and WHO guidelines, infants who receive a hepatitis B vaccine at birth have a substantially lower risk of chronic infection. By withholding the birth‑dose from a randomized group, the trial would have contravened this evidence base, leading to the ethical backlash. Experts especially from the African Union and the World Health Organization warned that a failure like this could erode trust in vaccination programs and undermine disease‑prevention efforts across the continent.
Open questions for the coming weeks focus on the precise reasons why the trial failed to secure necessary government approval. Early reports suggest that the application for ethical clearance may have been incomplete or that the investigators did not provide adequate safety data. Whether the judicial raid will result in legal action against the researchers remains unclear. Additionally, there is uncertainty over whether the $1.6 million CDC grant will be returned or reallocated, and how this setback will influence future U.S. funding for research in Guinea‑Bissau and other West African nations.
Stakeholders also worry that the trial’s abrupt halt could have a chilling effect on legitimate scientific enquiry in the region. A prominent African researcher argued that calls for “full transparency and robust oversight” are essential, noting that without them, beneficial trials could be repeatedly derailed by political or public pressure.
International health organizations have offered to support Guinea‑Bissau in strengthening its research regulation system. The WHO has stated that its guidelines include a requirement for vaccinations to begin at birth for hepatitis B, especially in high‑risk populations, and that studies deviating from this standard must provide robust justification and ethical safeguards. The absence of such safeguards in the WBHB trial is cited as a major reason for the ethics concerns. Meanwhile, the U.S. CDC has no official comment on the outcome of the investigation, but sources indicate that internal investigations are in progress to assess compliance with grant conditions.
In the days after the raid, the Bandim Health Project issued a brief statement expressing regret over the confusion created by the trial’s staging, while reaffirming its commitment to public health research. It also stated that its researchers would cooperate “fully with authorities to resolve the current issues.”
With the trial halted, Guinea‑Bissau now faces both an immediate health governance challenge and a longer‑term question of how to balance scientific inquiry with national ethical standards. As the investigation continues, international attention remains focused on ensuring that emergency vaccine trials—particularly those involving children—conform to the highest safety and ethical standards.
