Why Guinea-Bissau halted a controversial hepatitis vaccine trial for babies

Guinea-Bissau has reportedly halted a US-funded trial that planned to compare giving babies the hepatitis B vaccine at birth with giving it at six weeks. The project did not receive the required government approval, according to a researcher involved, after a review and public criticism over delaying a vaccine that the World Health Organization recommends at birth.

The trial was expected to involve about 14,000 babies, with researchers tracking their health for five years; it received $1.6 million from the US Centers for Disease Control and Prevention. Guinea-Bissau has a high burden of hepatitis B, and limited vaccine supplies currently mean the government allows vaccination up to six weeks after birth, while aiming to introduce birth doses for all babies from 2028. Experts called withholding the vaccine for research unethical, as infection in infancy can become chronic and cause serious liver disease.