In brief
The West African nation paused a U.S.‑financed hepatitis B vaccine trial led by Danish researchers that split newborns into two groups, one receiving the vaccine at birth and the other six weeks later. The trial, which intended to observe long‑term health outcomes for 14,000 babies, faced criticism for potentially denying lifesaving immunization to many infants. In October 2026, Guinea‑Bissau’s judicial police raided the project’s facilities in Bissau, seizing vaccine batches, and officials are examining compliance with national safety standards.
In Bissau, the capital of Guinea‑Bissau, regulators halted a United States‑funded hepatitis B vaccine study that would have left half of 14,000 newborns without a life‑saving shot for the first six weeks of life. The decision came amid criticism from health experts who argued that the design of the study violated ethical standards by withholding a WHO‑recommended vaccine from a randomly chosen group of infants.
The study, financed with $1.6 million from the U.S. Centers for Disease Control and Prevention, was led by Danish scientists Christine Stabell Benn and Peter Aaby of the Bandim Health Project, part of the University of Southern Denmark. The project had planned to enroll babies into two groups: one group would receive the hepatitis B vaccine immediately after birth, while the other would receive the same dose six weeks later. Researchers would then track health outcomes for five years to assess whether earlier vaccination provided better protection.
When the trial was announced in December last year, it sparked immediate backlash in Guinea‑Bissau and internationally. Health officials and independent reviewers warned that withholding a WHO‑recommended vaccine could expose thousands of infants to preventable disease. The pullback followed public outrage on social media and calls from medical associations to stop the study before it began.
In January 2026, the Guinea‑Bissau government paused the project and launched a formal review. The pause was described by one researcher involved in the project as a “significant setback” for African science. The researchers noted that the trial had failed to secure the necessary government approval before proceeding.
Mid‑October, the country’s judicial police raided the Bandim Health Project’s headquarters in Bissau. Police seized vaccine batches that had been earmarked for the study, and officials stated that investigations were underway to determine whether the trial met national safety standards. The raid was part of a broader inquiry into the legality of the study and the handling of the vaccine samples.
Officials from Guinea‑Bissau’s health ministry have not yet issued a formal statement on the raid. Nonetheless, the halt and subsequent police action indicate that the trial likely violated national regulatory requirements governing clinical research and vaccine use.
The controversy underscores a growing tension between global research initiatives and local oversight. While the U.S. Centers for Disease Control and Prevention said it was providing critical resources for disease prevention, the design of the study itself has been criticized for ignoring ethical norms that safeguard participants, especially vulnerable populations such as newborns.
Internationally, the World Health Organization reiterated in a statement that its hepatitis B vaccine recommendation is clear: the first dose should be given at birth to prevent mother‑to‑child transmission. The organization called the study design “contrary to best practice standards.”
“A life‐saving immunisation should not be withheld from newborns under any circumstances,” said a WHO representative in a statement.
Despite the pause, some scientists remain committed to further research on vaccine schedules. They anticipate that additional studies could help determine the optimal timing of hepatitis B vaccination in similar settings. However, they must now navigate stricter regulatory environments and restore trust with local communities.
As Guinea‑Bissau’s authorities continue to examine the trial’s compliance with safety regulations, the international community watches closely. The outcome of this case may influence how future research projects are designed and regulated in low‑resource settings, shaping the balance between innovation and the rights of participants.
