A proposed study that would have enrolled 14,000 newborns in Guinea-Bissau to compare hepatitis B vaccination at birth with vaccination beginning at six weeks will not move forward in the country because it did not receive required government approval, according to the lead researcher. The decision ends the immediate prospect of a trial that had prompted unusually sharp objections from the World Health Organization and other public-health experts.
The latest development also clarifies a confusing sequence of events around the study. A Danish university had approved a revised protocol in October, but that approval was conditional and did not permit the trial to begin without authorization from Guinea-Bissau. The study has produced no clinical results, and whether researchers will pursue a redesigned proposal remains unresolved.
Conditional university approval did not authorize the study
Frederik Schaltz-Buchholzer, the study’s lead researcher, said Oct. 21 that the project would not proceed in Guinea-Bissau because the necessary governmental approval had not been granted, The Guardian reported. The newspaper also reported that Guinea-Bissau’s health minister, Quinhin Nantote, had previously denied that the trial would go ahead.
Guinea-Bissau officials stopped the initial project in February amid international criticism, according to CIDRAP’s reporting on the February suspension. WHO said at the time that the country had suspended the research while further technical reviews were considered.
On Oct. 8, the University of Southern Denmark approved a revised protocol, an action that was sometimes described as the trial receiving clearance. But a university official told CIDRAP that final approval from Guinea-Bissau’s government remained necessary before the study could start. The later failure to gain that national authorization is therefore consistent with the trial never having begun.
The planned research was reported to have $1.6 million in funding from the U.S. Centers for Disease Control and Prevention, with an additional $1.6 million from private partners, The Guardian reported. But funding and institutional ethics approval are distinct from permission by a host country’s government to conduct research involving its newborn population.
The dispute centered on delaying a recommended birth dose
The research team had proposed randomly assigning newborns either to receive hepatitis B vaccine at birth or to receive no hepatitis B vaccine at birth. Under the described design, all children would receive hepatitis B vaccine at 6, 10 and 14 weeks through the existing immunization program. The Bandim Health Project’s account of the original protocol said the study was intended to examine possible broader, non-specific effects of the timing of the birth dose on outcomes such as mortality, hospitalization, skin conditions and neurodevelopment.
The proposed trial was not designed to test whether hepatitis B vaccination prevents hepatitis B infection. The protection offered by hepatitis B vaccines is already well established. The researchers’ question was whether administering the vaccine at birth, alongside live vaccines such as BCG, might affect other health outcomes. Their suggested biological rationale remains a hypothesis; because the study did not proceed, it generated no evidence that birth-dose vaccination improves or worsens overall survival, hospital admissions or development.
The trial team argued that its comparison reflected the country’s then-current practice, rather than denying participants a vaccine that newborns were routinely receiving. In its account of the original protocol, the Bandim Health Project said no enrolled child would receive fewer scheduled hepatitis B doses than provided under national policy at that time. Guinea-Bissau had decided in 2024 to add a hepatitis B birth dose to its routine schedule, with implementation planned by 2028.
WHO rejected the premise that the absence of universal routine access made a no-birth-dose control ethically acceptable. In a February statement, the agency said resource constraints do not justify withholding a proven intervention in research and said the publicly described design lacked adequate scientific justification and ethical safeguards. WHO’s assessment was based on the protocol descriptions available publicly and consultation with experts; it was not a finding from trial data.
Why public-health officials objected
WHO recommends that infants receive the first hepatitis B dose as soon as possible after birth, preferably within 24 hours, followed by at least two more doses. The agency says a timely birth dose prevents 70% to 95% of mother-to-child transmission cases. Infants infected around birth face a particularly high risk of chronic infection, which can later lead to cirrhosis and liver cancer.
The stakes are heightened in Guinea-Bissau, where WHO estimated that more than 12% of adults were living with chronic hepatitis B infection in 2022. That adult estimate does not establish how many newborns would have been exposed during the proposed trial, nor does it predict an individual child’s risk. It does help explain why a policy decision about timing of vaccination became a major ethical issue.
WHO also questioned whether the proposed single-blind, no-treatment-controlled design could reliably answer the broader health questions the researchers posed. In general, it said, a no-treatment vaccine control is appropriate only when no proven intervention exists or when such a design is indispensable. The trial team’s position was that the study compared existing practice with a policy that had been adopted but was not yet operating nationwide. The disagreement was therefore not over whether hepatitis B vaccine is safe or effective, but over whether it was justifiable to delay access to a recommended birth dose to investigate possible additional effects.
The episode leaves a practical gap between Guinea-Bissau’s decision to add the birth dose and its planned 2028 rollout. WHO’s recommendation supports delivery immediately after birth, but the available accounts do not establish whether the national introduction timetable will change.