Lead Researcher Says Hepatitis B Vaccine Trial in Guinea-Bissau Will Not Go Ahead
The lead researcher on a US-backed hepatitis B vaccine trial for newborns in Guinea-Bissau said on Wednesday, 21 October 2026, that the study will not go ahead there. The Guardian reported that the trial was halted by the researcher, Danish scientist Frederik Schaltz-Buchholzer. In a LinkedIn post, he wrote that it was "now clear" the study "will not move forward in Guinea-Bissau," because the team had not been given the necessary governmental approval.
The trial was to be funded with $1.6 million from the US Centers for Disease Control and Prevention (CDC), the federal public health agency, and another $1.6 million from private partners, including the Pershing Square Foundation and the Bluebell Foundation. The Danish team led by Schaltz-Buchholzer, Christine Stabell Benn and Peter Aaby had proposed testing whether live vaccines such as BCG may protect children against death from causes beyond the diseases they target, and whether giving the hepatitis B vaccine alongside them could weaken that effect. According to Schaltz-Buchholzer's LinkedIn article, the study would have tested 17,000 to 29,000 mothers for hepatitis B and immediately vaccinated 2,500 to 4,000 at-risk newborns. The protocol was amended to add that testing and immediate vaccination, to reduce risks to the control group, he said.
The government's position has differed. Guinea-Bissau's transitional government said on 13 October 2026 that it had not approved the trial, as Reuters reported. Health Minister Quinhin Nantote had earlier denied that the trial would move forward, calling that claim "not even remotely true." On Monday, 20 October, authorities searched the offices of the Bandim Health Project, a department of the country's National Institute of Public Health, and the government took control of the researchers' vaccines.
The trial drew strong criticism. Paul Offit, a vaccines expert at the Children's Hospital of Philadelphia, called the proposed study unethical and said the better course was to take the money and vaccinate as many children as possible. In February 2026, STAT News reported that the World Health Organization said the proposed trial, which would have left children without vaccine protection for six weeks, "is not ethical." Schaltz-Buchholzer wrote that the WHO country team in Guinea-Bissau had advised the country's National Immunization Technical Advisory Group against the trial. WHO spokesperson Tarik Jašarević said the organization recommends that all infants receive a first hepatitis B dose as soon as possible after birth, preferably within 24 hours, followed by at least two more doses.
The study had already faced a pause earlier in the year. In December 2025, a spokesperson for the US Department of Health and Human Services told Science that the trial was paused and "should proceed following further evaluation." In January 2026, CIDRAP reported that officials said the study was suspended pending review.
Guinea-Bissau currently gives BCG and oral polio vaccines at birth, and it plans to add a universal hepatitis B birth dose in 2028, according to Schaltz-Buchholzer. He also wrote that Africa bears about 25% of the global disease burden but hosts about 1% of clinical trials.
