The World Health Organization (WHO) has reaffirmed the effectiveness of the hepatitis B birth dose vaccine as a crucial public health intervention, noting that over 115 countries have incorporated it into their national immunization programs based on a record of safe and effective use spanning more than 30 years. The vaccine prevents transmission of the virus from mother to newborn, protecting against potentially life-threatening liver diseases, including cirrhosis and liver cancer, and is central to global elimination efforts.
The WHO’s statement comes in response to concerns surrounding a proposed clinical trial in Guinea-Bissau, which raised scientific and ethical questions, particularly regarding the potential for withholding the vaccine from a portion of study participants.
Concerns over Guinea-Bissau Trial
The WHO expressed “significant concerns” regarding the proposed randomized controlled trial (RCT) in Guinea-Bissau, stating that publicly available information raises questions about its scientific justification, ethical safeguards, and alignment with established principles for research involving human participants. The core concern centers on the study’s design, which, as initially proposed, involved administering the hepatitis B birth dose vaccine to some newborns while delaying vaccination for others until six weeks of age.
The WHO emphasized that the hepatitis B birth dose vaccine prevents 70–95% of mother-to-child transmissions. Withholding a proven, life-saving intervention exposes infants to the risk of chronic infection, with approximately 90% of newborns infected at birth becoming chronic carriers of the virus, potentially leading to severe complications later in life.
The organization further clarified that placebo or no-treatment arms in vaccine trials are only ethically acceptable when no proven intervention exists. Given the established efficacy and safety of the hepatitis B birth dose vaccine, the inclusion of a group not receiving the vaccine is scientifically questionable and ethically problematic.
Study Paused for Review
Guinea-Bissau has temporarily paused the study for further review. The WHO has offered technical support to accelerate the introduction of the birth dose vaccine, ensuring administration within 24 hours of birth, strengthening cold chain infrastructure, training healthcare workers, and monitoring coverage, and pharmacovigilance.
The controversy surrounding the trial has also drawn criticism from scientists worldwide, who have described the research as deeply unethical. The $1.6 million study, initially funded by the U.S. Centers for Disease Control and Prevention (CDC), aimed to assess the broader health effects of the vaccine, but the proposed methodology sparked widespread condemnation.
Reports indicate conflicting statements regarding the study’s status. While an official from the Africa Centres for Disease Control and Prevention (Africa CDC) stated at a briefing that the study had been canceled, a U.S. Department of Health and Human Services (HHS) official indicated that the study was proceeding as planned, with researchers continuing to refine the protocol.
Guinea-Bissau has one of the highest burdens of hepatitis B in the world, with nearly one in five people living with chronic hepatitis B infection. The WHO recommends universal hepatitis B vaccination at birth, as this is the most effective way to prevent lifelong infection.
In 2024, Guinea-Bissau committed to adding the birth dose to its national immunization program, with implementation planned for 2028. This decision reflects a commitment to protecting future generations based on sound scientific and ethical principles.
Hepatitis B causes hundreds of thousands of deaths annually worldwide. In Guinea-Bissau, chronic hepatitis B prevalence among adults exceeds 12%, with rates among children higher than global targets. The planned introduction of the birth dose vaccine represents a significant step towards reducing the burden of this preventable disease.
