A hepatitis B vaccine study in Guinea-Bissau, funded by the U.S. Centers for Disease Control and Prevention under the Trump administration, is undergoing further ethical review and has not been cancelled, Reuters reported, citing an official from the Africa Centres for Disease Control and Prevention (Africa CDC). The clarification follows conflicting reports last week over the trial’s status.

The study, led by the Bandim Health Project at the University of Southern Denmark, involves 14,000 newborns, all scheduled to receive the first dose at six weeks under Guinea-Bissau’s routine immunisation programme. Researchers say the trial is ethical because the children would not otherwise receive the vaccine at birth, and vaccination will be offered to mothers known to carry hepatitis B.

Africa CDC said Guinea-Bissau authorities requested additional technical and ethical guidance. A press briefing on the study’s status is expected Thursday. HHS officials told Reuters the trial is proceeding as planned, and Bandim researchers and local authorities were not immediately available for comment.

Critics argue that withholding the vaccine at birth is unethical in a country where hepatitis B prevalence is 19 percent. Paul Offit, director of the Vaccine Education Center at Children’s Hospital of Philadelphia, described the study as unethical, though he welcomed the additional review. Hepatitis B can be transmitted from mother to child at birth and may cause chronic infection, liver failure, or cancer.

Bandim researchers note that no child in the study receives fewer vaccines than outside it. They cite Denmark and the U.K., where the newborn dose is given only to babies of hepatitis B-positive mothers, and note that Guinea-Bissau plans to introduce a universal newborn dose, recommended by the World Health Organization, in 2028. The 1.6 million US dollar U.S.-funded study aims to inform global vaccine policy.