Guinea-Bissau Rejects US-Backed Hepatitis B Vaccine Trial in Newborns

A Small Nation Draws a Line

Guinea-Bissau has just become the latest country to confront a uncomfortable truth about global clinical research: when wealthier nations and well-connected advocates decide to run trials in poorer countries, the hosts often have little power to refuse.

On Tuesday, Guinea-Bissau’s health minister, Quinhin Nantote, held a press briefing and delivered a statement that carried more weight than the routine denials typical of understaffed ministries in West Africa. Guinea-Bissau had not approved a controversial hepatitis B study that would track nonspecific health outcomes in newborns — and had never agreed to the trial under the terms described in published proposals.

The timing was significant. Just days earlier, members of a Danish research ethics committee had been told that Guinea-Bissau had approved an updated study design. That information influenced several committee members to vote in favor of proceeding last week.

Guinea-Bissau was surprised. Its ministry was not consulted before that claim circulated.

“The ministry did not authorize the tests under the terms presented in the publications currently in circulation,” Nantote said, using the word “tests” rather than “study” — a subtle but telling refusal to grant the research any legitimacy.

The Trial That Would Withhold Vaccines

To understand why this story matters beyond West Africa, it helps to understand what the study actually proposes to do.

The trial would enroll 14,000 newborns in Guinea-Bissau. Half would receive the hepatitis B vaccine at birth, as is standard. The other half would be denied the immunization for the first six weeks of life.

Hepatitis B is widespread in Guinea-Bissau. Infection in early childhood can lead to lifelong liver disease and cancer. A safe and effective vaccine has existed for decades. The World Health Organization recommends a birth dose.

The trial is not designed to test whether the vaccine works. It is designed to track so-called “nonspecific” outcomes — overall mortality, neurodevelopmental conditions, and other health markers — in children who were or were not vaccinated at birth. The underlying hypothesis, championed by some researchers for years, is that vaccines may have broader effects on child health beyond the diseases they target, and that withholding the hepatitis B vaccine could reveal hidden harms.

This is the research agenda of Peter Aaby and Christine Stabell Benn, scientists behind the Bandim Health Project in Guinea-Bissau. Their work, conducted over decades, has argued that vaccines have nonspecific effects that may increase mortality from causes other than the targeted disease. The studies have been increasingly criticized for methodological shortcomings.

Charlotte Strøm, a Danish researcher who has examined their work, found that Aaby, Stabell Benn, and their collaborators reported no significant findings in 24 out of 25 studies. Strøm argued they chose not to publish results that did not support their hypotheses. “When researchers operate like this and abandon proper methodological rigor, they literally decide on the results themselves, and that is not science,” she said.

A Political Patron Enters the Frame

What makes this controversy distinct from ordinary disputes over research ethics is the political infrastructure now behind it.

Robert F Kennedy Jr., the US secretary of Health and Human Services, has publicly championed Aaby and Stabell Benn’s work. Kennedy has framed their findings as evidence that vaccine injuries are “hiding in plain sight” — language that directly echoes long-standing anti-vaccine narratives.

Under Kennedy’s leadership, the US Centers for Disease Control and Prevention has again set aside $1.6 million this year for the Guinea-Bissau trial, to be matched by private funding from the Pershing Square Foundation and the Bluebell Foundation. The US Department of Health and Human Services confirmed to Reuters that the study has not been approved, but has not responded to further questions about whether the funding will proceed.

This is no longer a marginal research dispute. It is a trial backed by a sitting US cabinet secretary, funded at the federal level, and promoted by someone who built his public profile opposing vaccines.

The Ethics Committee That Changed Its Own Rules

In Denmark, the scandal unfolded within the National Committee on Research Ethics in Biomedicine. Four members resigned after the committee fast-tracked approval for the Guinea-Bissau trial. The committee’s own rules had to be amended because randomized controlled trials fell outside its original mandate — a procedural workaround that allowed the vote to proceed without the scrutiny such a study would normally require.

When committee members asked for more information about Guinea-Bissau’s supposed approval, they received none.

The contradictions are stark. Denmark does not routinely vaccinate infants against hepatitis B. The country tests widely, has low incidence, and maintains a healthcare system capable of tracking health outcomes in real time. If this study were genuinely about understanding vaccine effects, Denmark would be the natural location. Instead, it is being proposed for a country with limited resources and a transitional military government that came to power after a coup in November 2024.

“It’s completely unethical that this trial is even proposed,” said BK Titanji, a researcher at Emory University. “A study like this needs the highest level of ethical scrutiny. You are going to be conducting a study on the most vulnerable population, which is newborn babies, in a country that is resource constrained.”

What Guinea-Bissau’s Resistance Means

Guinea-Bissau’s pushback should not be taken for granted. Small nations in West Africa routinely host clinical trials sponsored by foreign institutions, often with limited bargaining power. The fact that Guinea-Bissau’s health minister convened an emergency meeting with the Bandim Health Project, the local ethics committee, the National Institute of Public Health, and the Expanded Vaccination Program — and then publicly denied authorizing the trial — is unusual.

The foreign minister, João Bernardo Vieira, was blunt in February: “It’s not going to happen, period.”

Guinea-Bissau also requested that the Africa Centres for Disease Control and Prevention send experts to evaluate the study. The WHO has offered to support the country in rolling out the hepatitis B birth dose for all newborns — the standard, proven public health intervention — rather than fund a trial that would deliberately withhold it from half of them.

Colette Delawalla, founder of Stand Up for Science, called Guinea-Bissau’s stance a meaningful assertion of sovereignty. “For the government of Guinea-Bissau to stand up against the United States and Denmark exploiting its children is no small statement,” she said.

The economics are simple enough to state without rhetoric. It costs approximately $13,200 to vaccinate all newborns in Guinea-Bissau each year through Unicef and Gavi. Every child would receive the birth dose. The trial, by contrast, would deny half of them a vaccine that prevents a disease that kills and disables.

The Broader Implications

The Guinea-Bissau case is a stress test for the global governance of clinical research. It raises questions that extend far beyond one West African nation.

Who decides when a trial is ethical? The researchers proposing it? The ethics committees reviewing it? The communities where it would be conducted? Or the governments that must bear responsibility for what happens to their citizens?

The current system allows foreign ethics committees to approve trials that will take place in other countries, sometimes based on information that the host country disputes. It allows federal agencies in wealthy nations to fund research that host governments have not authorized. It allows researchers with established agendas to continue running studies in low-income countries even as their methods face scrutiny at home.

Denmark’s experience with this trial — the rule changes, the resignations, the lack of transparency — suggests that even institutions with strong ethical frameworks can be pressured into expedited approvals when political and financial stakeholders demand action.

The outcome in Guinea-Bissau is not yet final. The CDC funding remains allocated. Kennedy’s department has not ruled out proceeding. But the country has drawn a line, and the line is one that the research sponsors will have to confront.

For now, the most ethical path is the simplest one: vaccinate every newborn in Guinea-Bissau against hepatitis B, at birth, for $13,200 a year. The trial was never necessary. The only question now is whether it will happen anyway.