The $1.6 million study, funded under the purview of Robert F. Kennedy Jr., a known vaccine skeptic, and the U.S. Department of Health and Human Services (HHS), sparked outrage due to ethical concerns surrounding the withholding of hepatitis B vaccines from newborns in a region with a high prevalence of the disease. The study's premise involved evaluating alternative vaccination schedules, raising questions about the necessity of delaying or withholding proven protection against hepatitis B.

Hepatitis B is a viral infection that attacks the liver and can cause both acute and chronic disease. According to the World Health Organization (WHO), it is a major global health problem, particularly in Africa and Asia. The virus is most commonly spread from mother to child during birth and delivery, as well as through contact with infected blood or other body fluids. Vaccination is a highly effective method of preventing hepatitis B infection, and the WHO recommends that all infants receive their first dose of the hepatitis B vaccine as soon as possible after birth, preferably within 24 hours.

The ethical concerns stemmed from the potential risks to newborns who might have been exposed to the virus but not immediately vaccinated as per standard protocol. Critics argued that withholding or delaying vaccination, even for research purposes, was unacceptable given the availability of a safe and effective vaccine and the high burden of hepatitis B in Guinea-Bissau.

"It's of importance for Africa CDC to have evidence that can be translated in policy, but this has to be done within the norm," Boum stated, suggesting the study's methodology deviated from accepted ethical standards for research involving human subjects.

The cancellation raises questions about the oversight of US-funded research projects in developing countries and the need for stringent ethical review processes to ensure the well-being of participants. The Africa CDC's intervention highlights the growing role of African institutions in safeguarding the ethical conduct of research on the continent. Further details regarding the specific reasons for the cancellation and the future of hepatitis B prevention efforts in Guinea-Bissau are expected to be released in the coming weeks.