A controversial research trial that will withhold hepatitis B vaccines from some newborns in Guinea-Bissau has received approval to proceed this week. This trial is a central element of the vaccine strategy promoted by Robert F. Kennedy Jr., the US Secretary of Health and Human Services and a vocal vaccine opponent.

At an anti-vaccine conference last month, Kennedy lauded the Danish researchers behind the trial. He presented US-supported research on hepatitis B in newborns as an example of the Trump administration's vaccine agenda, which has involved reducing vaccine recommendations and questioning the safety and efficacy of vaccines.

Paul Offit, an infectious disease physician at Children's Hospital of Philadelphia, stated that Kennedy's objective is to eliminate the birth dose of the hepatitis B vaccine in the United States. Offit added that such a trial would not be possible in the US due to significant ethical concerns, suggesting Kennedy is exploiting a developing nation.

Danish researchers intend to enroll 14,000 infants in Guinea-Bissau. Half of these infants will receive the hepatitis B vaccine at birth, while the other half will have its administration delayed for the first six weeks of life. An ethics committee at the University of Southern Denmark voted to approve the trial this week. Guinea-Bissau officials have also given the project the green light, despite the health minister, Quinhin Nantote, having previously stated it was suspended following international outcry earlier this year.

Stig Børsen Hansen, one of the reviewers who presented the study to the Danish committee, resigned on Friday in protest, citing major ethical issues. He described the trial as "enrolling newborns in a lottery to test a hypothesis."

This trial's approval has drawn criticism from public health experts who argue that delaying vaccination for any infant increases the risk of transmission and infection, particularly for a virus like hepatitis B, which can cause chronic liver disease, cirrhosis, and cancer.

The hepatitis B vaccine is recommended by global health organizations for administration at birth to prevent vertical transmission from mother to child and to protect infants from early-life exposure. The World Health Organization and the Centers for Disease Control and Prevention both strongly advocate for this practice.

Questions remain about the funding sources for the research and the long-term follow-up protocols for the infants involved in the trial, especially for those whose vaccination is delayed.