Outcry Forces Cancellation of U.s.-backed Infant Vaccine Trial in Africa

WHO:

Defector - The proposed trial was designed by Danish researchers Christine Stabell Benn and Peter Aaby of the Bandim Health Project, which has operated in Guinea-Bissau since 1978.

Defector - The U.S. Centers for Disease Control and Prevention (CDC) funded the study; the article says the grant was awarded to researchers at the University of Southern Denmark.

Defector - Guinea-Bissau’s transitional government and police force took action against the trial; the country was under a transitional military government following a coup.

Defector - David Boulware, an infectious-disease physician at the University of Minnesota, criticized the plan; Jeremy Faust discussed design flaws at Inside Medicine.

Defector - Four members of the University of Southern Denmark ethics committee resigned in protest after it voted to proceed.

Ars Technica - The article describes the study as a U.S.-backed trial involving babies and reports that it was canceled after international outcry.

WHAT:

Defector - The CDC awarded $1.6 million for a proposed hepatitis B vaccine trial involving 14,000 newborns: 7,000 would receive the vaccine at birth and 7,000 would wait until six weeks.

Defector - The trial sought to study possible “non-specific effects” of the hepatitis B vaccine, including skin disorders and neurodevelopmental conditions.

Defector - Guinea-Bissau police announced a raid on the Bandim Health Project’s offices and seizure of hepatitis B vaccine doses; the transitional government then said it would not authorize the trial.

Ars Technica - The trial was canceled before police seized the vaccine doses.

Defector - The country recommends hepatitis B vaccination at six weeks and plans universal vaccination at birth in 2027.

Defector - Nearly one in five people in Guinea-Bissau have chronic hepatitis B; around 90 percent of exposed newborns develop chronic infection, and 25 percent of those children eventually die of hepatitis B-related liver cancer or liver failure.

Defector - The proposed trial’s revised protocol would screen mothers; babies of mothers testing positive would be vaccinated and excluded, while babies of mothers testing negative would have a 50 percent chance of not receiving the vaccine.

WHERE:

Defector - The trial was proposed for Guinea-Bissau, a West African country.

Defector - The researchers were affiliated with the University of Southern Denmark; the Bandim Health Project operated in Guinea-Bissau.

WHY:

Defector - The researchers proposed the study to compare health outcomes among newborns vaccinated at birth and newborns whose vaccination was delayed until six weeks.

Defector - Critics said withholding vaccination exposed infants to hepatitis B infection and violated research ethics; Boulware wrote that consigning infants to a high risk of infection was “unthinkable.”

Defector - Guinea-Bissau’s transitional government declined to authorize the trial after it drew international criticism.

HOW:

Defector - The CDC funding was announced on Dec. 18, 2025, and the protocol was leaked to Inside Medicine in January.

Defector - An ethics committee at the University of Southern Denmark approved proceeding with a revised protocol; four committee members resigned in protest. Reviewer Stig Børsen Hansen told The Guardian, “You are now enrolling newborns in a lottery to test a hypothesis.”

Defector - The revised protocol proposed testing mothers for hepatitis B before birth, but the article says the test has a 5 percent false-negative rate.

Defector - The article reports that the police announced the raid on Facebook and that the government subsequently announced it would not authorize the study.

(UPDATED October 23, 2026 16:21 UTC)

A U.S.-funded hepatitis B vaccine trial involving 14,000 newborns in Guinea-Bissau has been canceled after international criticism and opposition from the country’s transitional government. Researchers planned to compare babies vaccinated at birth with babies whose shots were delayed until six weeks, studying possible effects on health and development. Critics said delaying the vaccine would expose infants to a serious infection, especially in a country where nearly one in five people has chronic hepatitis B. The trial was designed by Danish researchers with the Bandim Health Project, which has worked in Guinea-Bissau since 1978, using a $1.6 million CDC grant. A revised plan would have screened mothers, but critics raised concerns about false-negative results. Four University of Southern Denmark ethics committee members resigned after the committee approved proceeding. Police announced plans to raid the project’s offices and seize vaccine doses; the government then said it would not authorize the study.