14,000 Newborns in Guinea-Bissau Set for Hepatitis B Vaccine Trial

Fourteen thousand newborns in Guinea-Bissau will be enrolled in a research trial that withholds the standard hepatitis B birth dose from half of them for six weeks, after a Danish ethics committee and health officials in the West African country approved the project this week, according to the Guardian.

The trial is run by researchers from the University of Southern Denmark. It is also a piece of the vaccine policy pushed by Robert F. Kennedy Jr., the U.S. secretary of health and human services, who praised the Danish team at an anti-vaccine conference last month, the Guardian reported.

What does the trial actually test?

Researchers plan to split 14,000 infants into two groups, the Guardian reported. Half will get the hepatitis B vaccine at birth, the standard practice recommended by global health bodies. The other half will not receive the shot until they are six weeks old. The goal, according to the Guardian's reporting on Kennedy's remarks, is to generate data that could support dropping the birth-dose recommendation in places like the United States.

Hepatitis B spreads through blood and body fluids and can pass from mother to infant during birth. The birth dose is designed to protect newborns in the earliest, most vulnerable window before other protections are in place.

Who signed off on the trial this week?

An ethics committee at the University of Southern Denmark voted this week to let the trial proceed, the Guardian reported. Officials in Guinea-Bissau also approved the project. That approval reverses an earlier pause: the country's health minister, Quinhin Nantote, had said the trial was suspended after what the Guardian described as international uproar earlier this year.

The back-and-forth over approval status in Guinea-Bissau means the trial's path has not been a straight line from proposal to launch. It was paused once already before this week's go-ahead.

Why did an ethics reviewer quit over it?

Stig Børsen Hansen, a founding member of the Danish ethics committee and one of two reviewers who presented the study to the panel, resigned on Friday in protest, the Guardian reported. He said the study put infants at risk without adequate justification.

"You are now enrolling newborns in a lottery to test a hypothesis," Hansen said, according to the Guardian.

Paul Offit, an infectious disease physician at Children's Hospital of Philadelphia, raised a related concern about where the trial is happening. "He's taking advantage of a developing country," Offit said of Kennedy, per the Guardian. "Is it because children in Africa are more expendable than children here?" Offit also said Kennedy would not be able to run this kind of trial in the United States because of the ethical concerns it raises.

How does RFK Jr. fit into this?

Kennedy has spent his time at HHS cutting vaccine recommendations and raising doubts about shot safety and effectiveness, the Guardian reported. At last month's anti-vaccine conference, he held up the Danish research as an example of what he wants for U.S. policy, saying he wants to stop using a birth dose of hepatitis B vaccine in the United States, according to Offit's account relayed to the Guardian.

Offit summarized the stakes bluntly: "That's the goal."

Timeline: how the trial moved from pause to approval

• Earlier in 2026: International criticism leads Guinea-Bissau's health minister, Quinhin Nantote, to say the trial is suspended, per the Guardian.
• Last month: Kennedy praises the Danish research team at an anti-vaccine conference, calling it central to his vaccine agenda, the Guardian reported.
• This week: The University of Southern Denmark ethics committee votes to let the trial proceed; Guinea-Bissau officials also give their approval.
• Friday: Stig Børsen Hansen resigns from the ethics committee in protest, citing the risk to enrolled newborns.

What to watch next

• Whether Guinea-Bissau's government issues any further statement given the earlier suspension and this week's reversal.
• Whether other members of the Danish ethics committee follow Hansen in resigning or speaking out.
• Whether HHS under Kennedy references trial data, once available, in any move to change U.S. hepatitis B birth-dose recommendations.
• Whether international health bodies or other governments weigh in on enrollment now that the trial has cleared both Danish and Guinea-Bissau approval.

For now, the trial's design remains as the Guardian reported it: 7,000 newborns get the vaccine at birth, and 7,000 wait six weeks, with the outcome expected to shape arguments on both sides of the birth-dose debate for years to come.

Artiglio is A coming-soon iPhone chief of staff for briefings and drafts. Not on the App Store yet.