// ARS TECHNICA — MODA & SOCIETÀ
US-backed vaccine trial on babies canceled after international outcry
The decried trial was canceled last week before police seized vaccine doses.
Government officials in Guinea-Bissau have formally rejected a clinical trial that would be run by Danish researchers and funded by the US to look for alleged nonspecific harms from the newborn dose of the hepatitis B vaccine. The vaccine dose is currently recommended globally for all newborns and has been used safely and effectively for decades.
In an email to Ars Technica, one of the trial’s lead researchers, Christine Stabell Benn of Bandim Health Project and the University of Southern Denmark, said that Guinea-Bissau’s Council of Ministers “formally reaffirmed its non-acceptance of the study on 16 October.”
The revelation that the study was formally rejected last week comes after news on Monday that judicial police in Guinea-Bissau raided Bandim Health’s offices and seized vaccines. Stabell Benn highlighted that the police search came after the trial was rejected.
Of the trial’s rejection, Stabell Benn wrote: “We regret the decision because we considered the study scientifically and ethically justified, but we respect the government’s authority to decide whether research may proceed in the country.”
The World Health Organization and many outside experts have sharply disagreed with Stabell Benn and her colleagues on the trial’s justifications and design. It has been widely decried as “unethical” because it would withhold the newborn dose of hepatitis B vaccine from half of the participants.
With the country’s high rates of chronic hepatitis B infections, this would put thousands of babies at risk of developing a lifelong infection that can lead to liver cirrhosis, cancer, and premature death. Experts have further said that there is no scientific justification for the study, given the vaccine’s long use and strong safety record. The WHO wrote in February that the trial “posits hypothetical safety outcomes without sufficient credible evidence” to justify putting newborns at risk.
Outrage erupted over the trial after the US Centers for Disease Control and Prevention announced in December that it had awarded an unsolicited grant of $1.6 million to Bandim Health, which Stabell Benn runs with her husband Peter Aaby. The researchers are known for pursuing studies on nonspecific harms from vaccines and have been lauded by anti-vaccine advocates, including US Health Secretary Robert F. Kennedy. But Aaby and Stabell Benn’s scientific peers have been critical of the quality of their work; the researchers are currently under investigation by Danish authorities for alleged scientific misconduct in their previous studies.
Their hepatitis B vaccine trial was reportedly halted in January by Guinea-Bissau authorities. But outcry erupted again after a report that the US CDC, under Kennedy, had once set another $1.6 million aside to fund the trial and intended to move forward with it.
Stabell Benn and colleagues have publicly lamented their tie to Kennedy. They have also consistently argued that their hepatitis B study is not unethical because Guinea-Bissau does not currently offer routine hepatitis B vaccine doses to newborns. Therefore, newborns not given the vaccine in the trial wouldn’t have received it outside the trial anyway. The country—which experienced a coup in November 2025—plans to introduce a birth dose in 2028, but it lacks the resources and infrastructure to do so now.