Arya News - Experts have said the US-funded trial would deny critical vaccines to thousands of infants.
Guinea-Bissau has reportedly halted a controversial United States-funded hepatitis B virus vaccine (HBV) trial which drew global scrutiny when experts said it involved withholding lifesaving shots from thousands of babies.
The trial failed to gain the necessary government approval, one researcher involved in the project said in a statement, adding that the end of the trial was a “significant setback” for African science.
Officials have not commented.
The West African nation’s judicial police said in mid-October that it had raided the facilities of the research group leading the project in the capital, Bissau, and seized vaccine batches.
Authorities said inquiries were continuing to determine whether the trial had complied with the country’s safety standards.
Here’s what we know:
A box of hepatitis B vaccine is displayed at a CVS Pharmacy, on September 9, 2025, in Miami, Florida [Rebecca Blackwell/AP] What was the trial about?
The trial was designed to assess the effects of World Health Organization (WHO)-recommended HBV vaccines on two groups of babies. One group would receive the vaccine at birth, and another, chosen at random, would receive it six weeks later.
Some 14,000 babies were expected to be involved in the trial. The researchers planned to assess health outcomes over five years for the two sets.
The project secured $1.6m from the US Centers for Disease Control and Prevention (CDC) under Health Secretary Robert F Kennedy, who has previously made his anti-vaccine views known.
However, the announcement of the trial in December last year met with widespread anger over the withholding of the vaccine from one set of babies. In January, the Guinea-Bissau government paused the project and launched a review.
Who was leading the trial?
The Danish research group, Bissau-based Bandim Health Project, part of the University of Southern Denmark, planned the trial.
It is chaired by prominent scientists Christine Stabell Benn and Peter Aaby, a married couple. Since 1978, they have run the Bandim Health Project out of Bissau and have conducted studies on thousands of Bissau-Guineans.
Both researchers primarily study unintended impacts of vaccines and have theorised that vaccines which contain inactivated viruses can cause death, including the HBV vaccine which they planned to test in Bissau.
Their counterparts in Denmark have, however, repeatedly accused them of downplaying trial results or withholding evidence that does not align with their narrative.
One of the pair’s studies found that WHO-approved vaccines against diphtheria, tetanus and pertussis (DTP) led to higher infant deaths, especially for girls. WHO said the pair’s study was inconsistent but merited further review, and advised countries to keep vaccinating babies.
Last February, investigations by the Danish publication, Weekendavisen, found that the researchers had not publicised the null results of one of their randomised controlled trials (RCTs) on the DTP vaccine conducted 14 years ago. The study was published after the expose.
Why is the hepatitis B trial controversial?
In this case, health experts questioned the morality of withholding a highly effective vaccine from thousands of babies for the purposes of research. WHO called it “unethical”.
Infants are at the highest risk of being chronically infected with hepatitis B – usually passed to them from their mothers. The disease has no cure and can lead to long-term liver damage and cancer. WHO recommends HBV vaccines at birth for all babies, as well as booster shots, which are known to offer years of protection.
Guinea-Bissau has one of the highest numbers of people living with hepatitis B – one-fifth of the 2.2 million population. Because it cannot access enough doses, the government authorises the vaccine at up to six weeks after birth. However, it is working to start at-birth hepatitis B vaccination for all babies from 2028.
The researchers argued that the timeframe between now and 2028 provides a “unique window of opportunity” to assess how the vaccine affects babies who receive it at birth against those who receive it after six weeks. They noted that the research would see thousands of babies receive the shot at birth before the official schedule kicks in.
But health experts pushed back, saying the study would essentially hold back vaccines from the other half who would have had access to it if the government in Bissau could afford it. They said the effects, if some babies do develop hepatitis B, could last for a lifetime.
“[The researchers] took advantage of the fact that Guinea-Bissau does not have a very strong research capacity … a very strong critical mass of public health professionals, very well vested in understanding what the politics that surround global health are,” Magda Robalo, a former Guinea-Bissau health minister, told Al Jazeera.
“It is unethical to deny children an intervention that we know works, that will contribute to improving their lives and save them from a disease that we know they will likely acquire,” she added.
Some also questioned why the researchers planned to make the trial “open label”, meaning the researchers would know which participants received the vaccines, and when. Such randomised trials are usually conducted “blind”.
Others pointed out that the trial is reminiscent of the Tuskegee trial in Alabama, US, which saw health authorities study effects of untreated syphilis in Black men between 1932 and 1972, even though penicillin treatments were available at the time. More than 100 men died.
What have the researchers said?
Benn denied any wrongdoing in the group’s work in an email to Al Jazeera in February this year.
In a joint statement, Benn and Aaby further clarified that they were not testing whether the HBV vaccine prevents the disease, but “whether the prevention [of the disease] comes at a prohibitive price”, such as death and other health outcomes.
They accused their critics of lacking curiosity and a “humble” mindset, and said the research would add to a scientific body of work on the topic.
How has Guinea-Bissau responded?
Guinea-Bissau launched an inquiry into the trial in conjunction with the Africa Centres for Disease Control and Prevention (Africa CDC) and the WHO in January.
Officials also claimed the country’s transitional government, which took power following a November coup, had not been involved in the approval process.
A Danish ethics committee investigating the issue separately reportedly received information that Guinea-Bissau had approved an updated proposal, causing its members to vote that the project continue.
However, Health Minister Quinhin Nantote denied that report in a media statement in mid-October, following a meeting with the researchers and local health agencies.
On October 19, police raided and seized batches of the vaccine from Bandim facilities. Authorities also appear to have cancelled the trial.
“It is now clear that the hepatitis B-NSE trial will not move forward in Guinea-Bissau – we were not given the necessary governmental approval, Bandim researcher Frederik Schaltz-Buchholzer said in a LinkedIn post a few days later.