The proposed trial of a hepatitis B vaccine on newborn babies in Guinea-Bissau – funded by the US but cancelled after being slammed as “unethical” and “neo-colonial” – has raised broader questions by health experts about whether vulnerable populations in African countries are being asked to take risks that researchers would not accept in wealthier countries, reports the BBC.
Police have since seized a batch of vaccines from the research centre at the heart of the controversy, which planned to withhold a vaccine recommended by the World Health Organisation (WHO) from half of the participating newborns.
As reported in MedicalBrief, the study was planned at the Bandim Health Project, a research centre that has operated in Guinea-Bissau since 1978, and intended to involve 14 000 newborns, with half receiving a hepatitis B vaccine shortly after birth and the other half not being given the shot.
Bandim said the trial aimed to investigate whether the vaccine given at birth has broader health effects beyond preventing infection.
Previous studies in The Gambia and Guinea-Bissau have raised questions about a possible link to increased mortality.
Researchers argued that because Guinea-Bissau does not currently offer routine hepatitis B vaccinations at birth, despite WHO recommendations, they have a unique opportunity to study its effects before such vaccines are introduced in 2028.
However, critics questioned the ethics of withholding the vaccine from some babies, particularly in one of the world’s poorest countries, where the infection is widespread.
The Trump administration funded the proposed study, with the CDC awarding the University of Southern Denmark (SDU) $1.6m in December 2025.
What the WHO said
Walter Kazadi Mulombo, the WHO representative in Guinea-Bissau, told the BBC they became concerned after receiving questions about the study and finding no publicly available protocol.
He said the main ethical concern was that the trial would withhold an intervention already proven to protect newborns against hepatitis B.
“The vaccine has been used for more than 30 years in more than 115 countries,” he said. “A study that will withhold that intervention from other newborns is unethical.”
He warned that babies could be exposed to the virus during childbirth if their mothers were infected, as well as later in life. Nearly a fifth of the population of Guinea-Bissau is infected with hepatitis B.
Those infected during infancy are particularly likely to develop chronic infections, which kill up to 25% of people, mostly through liver failure or liver cancer, according to data published in 2020.
The WHO is working with the government to bring forward the birth-dose vaccine.
“The country had been expected to add it to its routine immunisation schedule in 2028, but officials are considering introducing it in the first quarter of next year,” Mulombo said.
Guinea-Bissau currently vaccinates children against hepatitis B at six weeks, which means it is less effective.
Why Guinea-Bissau rejected the trial
The country’s government prohibited the trials in January, at the time, requesting a team of experts from the Africa Centres for Disease Control and Prevention (Africa CDC) to help evaluate the study.
Health Minister Quinhin Nantote said in October that the suspension remained in force and had not been overturned by the Council of Ministers after reports emerged claiming that the trial would be taking place after all.
The dispute intensified after the SDU said a revised study protocol had received ethical approval “from the relevant authorities in Guinea-Bissau”, which Nantote denied.
Dr Gavin Yamey, a professor of global health and public policy at Duke University in the US, criticised the trial proposal.
“It reeks of neocolonialism,” he told the BBC, questioning why the research was not being conducted in Denmark.
SDU dean Jakob Grauslund said the trial had never started, no babies had been enrolled and no vaccinations administered as part of the research. He added that it had received a separate, positive assessment from the university’s own research ethics committee, and had also sought an additional independent assessment, although Danish law did not require one.
He added that the relevant Danish statutory research ethics bodies were unable to undertake the review.
After the approval from the SDU’s ethics committee, Grauslund decided that the project could proceed. He stressed, however, that this did not replace the separate authorisation required from Guinea-Bissau’s authorities.
Vaccines seized
On 19 October, Guinea-Bissau's Judicial Police searched the Bandim Health Project’s facilities in the capital, Bissau, and seized a batch of hepatitis B vaccines.
They did not disclose how many doses had been seized or the specific grounds for the investigation. Grauslund said he could not comment on the seizure of the vaccines.
Who is funding the research?
The proposed trial was funded by the US Government at a time of significant changes to vaccine policy under President Donald Trump and Health Secretary Robert F Kennedy Jr.
Under Kennedy’s leadership, a US vaccine panel attempted to end a longstanding recommendation that all newborns receive a hepatitis B vaccine at birth, but a federal judge later blocked this, along with other changes to vaccine policy made by the Trump administration.
Critics have questioned whether the research could help support that policy shift, although the study’s stated aim was to investigate potential effects of the vaccine beyond preventing infection.
Kennedy has praised the Danish researchers as “the deities of vaccine research”, and cited earlier findings from their work in support of concerns about vaccine safety. A subsequent study by some of the same researchers, however, found no evidence of the previously reported effect.
BBC article – Why a US-funded vaccine trial on babies was cancelled in Guinea-Bissau (Open access)
See more from MedicalBrief archives:
Guinea-Bissau denies approving hepatitis vaccine trial
WHO slams US-funded baby vaccine trial in Guinea-Bissau
Controversial study will delay life-saving vaccine for Guinea-Bissau babies