An ethics committee at the University of Southern Denmark gave the go-ahead this week for a research project that will withhold the hepatitis B vaccine from a portion of newborns in Guinea-Bissau. The study, championed by U.S. Health and Human Services secretary Robert F. Kennedy Jr., plans to enroll 14,000 infants administering the vaccine at birth to half of them while the other half will wait six weeks before receiving their first dose.
How the trial is structured and who is involved
The protocol calls for mothers to be screened for hepatitis B before delivery. Babies whose mothers test positive will be vaccinated immediately and excluded from the experimental arm. Those whose mothers test negative may be randomized: the “lottery” determines whether a child receives the birth dose or is placed in the delayed-vaccination group. Researchers will follow the children for outcomes such as mortality, skin conditions and neurodevelopmental markers. The hepatitis B test used in the screening process carries a 5% false-negative rate meaning some infected parents could be missed and their infants would be placed in the unvaccinated cohort under false reassurance.
Guinea-Bissau bears one of the world’s highest hepatitis B burdens, with roughly 18% of adults testing positive. Transmission can occur during birth, but also through everyday contact—shared washcloths, toothbrushes or fingernail clippers—as the virus can survive on surfaces for up to seven days. Infants infected in their first year face a markedly higher risk of chronic disease and liver cancer.
Ethical backlash and resignations
The study has ignited fierce criticism from public-health experts. Infectious-disease physician Paul Offit described the design as “enrolling newborns in a lottery to test a hypothesis” and warned that denying a proven preventive measure “places children at unnecessary risk.” He added that such a protocol could not be run in the United States because of its “significant ethical concerns” and questioned whether “children in Africa are more expendable than children here.”
Stig Børsen Hansen, a founding member of the Danish review panel, resigned on Friday, calling the experiment “by design” a mechanism that would cause infection in the “losers” of the lottery. Three additional committee members followed suit, citing the same moral objections. The Helsinki Declaration mandates that international medical research obtain approval from ethics committees in both the sponsor and host nations, a requirement critics say is being stretched to accommodate a study that deliberately withholds a life-saving intervention.
Funding sources and political context
The United States Centers for Disease Control and Prevention has earmarked $1.6 million from this year’s budget for the project, a sum that will be matched by private contributions from the Pershing Square Foundation—co-founded by billionaire activist Bill Ackman—and the Bluebell Foundation. Kennedy has publicly praised the Danish investigators, labeling them “the deities of vaccine research” at an anti-vaccine conference and framing the trial as a hallmark of the current U.S. administration’s stance on immunisation policy.
While the Danish ethics panel—traditionally focused on non-clinical studies—altered its rules to consider this trial, a majority of its members voted in favour despite internal dissent. At Aarhus University, statistics professor Henrik Støvring warned that decades of evidence demonstrate the vaccine’s benefit, making it “unfair” to randomise children into a group that forgoes a proven protection. He noted that Denmark itself does not routinely give the birth dose unless the mother is hepatitis B positive, a practice that could have served as a more appropriate setting for the research.
The local partner, the Bandim Health Project, run by Danish scientists Peter Aaby and Christine Stabell Benn, has long been embedded in Guinea-Bissau’s health system. The nation’s health minister, Quinhin Nantote, initially announced the study’s suspension after international outcry earlier this year, but later confirmed approval, aligning the trial’s timeline with a postponed national rollout of universal newborn hepatitis B vaccination originally slated for 2027 and now pushed to 2028.
As debates continue, the ethical question remains: does a delayed-vaccination design, backed by U.S. federal funds and private philanthropy, outweigh the potential harm to infants who may contract hepatitis B during the six-week window? The answer will likely shape future international research collaborations and set a precedent for how vaccine trials are conducted in low-resource settings.
