WHO Condemns Unethical Hepatitis B Vaccine Trial & Reaffirms Birth Dose Importance

The World Health Organization (WHO) has publicly criticized a planned randomized controlled trial (RCT) for the hepatitis B birth dose vaccine in Guinea-Bissau, calling the study “unethical” and inconsistent with established scientific and ethical principles. The trial, funded by the United States, proposes to withhold the vaccine from a portion of newborns, a practice the WHO asserts exposes infants to serious, potentially irreversible harm.

The hepatitis B birth dose vaccine has been a core public health intervention for over three decades, utilized in the national immunization schedules of more than 115 countries. It is designed to prevent mother-to-child transmission of the virus, which can lead to chronic infection, cirrhosis and liver cancer. According to the WHO, the vaccine is effective in preventing 70–95% of such transmissions.

The WHO’s concerns center on the study’s design, which includes a “no-treatment arm” where some newborns would not receive the vaccine. The organization argues that withholding a proven, life-saving intervention when no scientific necessity exists is ethically unacceptable. “A study which provides the hepatitis B birth dose vaccine, a proven lifesaving intervention, but withholds it from some study participants exposes newborns to serious and potentially irreversible harm,” the WHO stated.

The WHO also questioned the scientific justification for the trial, noting that publicly available descriptions do not challenge the established efficacy of the birth dose vaccine. Instead, the protocol focuses on hypothetical safety outcomes without providing sufficient evidence of a safety signal that would warrant exposing participants to risk. The organization further criticized the single-blind, no-treatment-controlled design, citing a significant risk of bias and limited policy relevance.

“No scientific necessity for a no‑treatment arm: Placebo or no‑treatment vaccine trials are only acceptable when no proven intervention exists or when such a design is indispensable to answer a critical question of efficacy or safety,” the WHO stated. “Neither condition appears to be met based on publicly available descriptions of the study.”

Guinea-Bissau formally decided in 2024 to add the hepatitis B birth dose to its national immunization schedule, with full implementation planned by 2028. This decision, according to the WHO, further underscores the ethical concerns surrounding the trial, as it affirms the vaccine’s value and the importance of timely protection for newborns.

The WHO emphasized that resource constraints cannot justify withholding proven care in a research study. The organization has offered support to Guinea-Bissau as it reviews the trial and works to accelerate the introduction of the birth dose vaccine, including strategies for delivery within 24 hours of birth, antenatal screening for hepatitis B, and strengthening cold-chain logistics and healthcare worker training.

As of February 15, 2026, Guinea-Bissau has suspended the study pending further technical reviews. The WHO remains committed to working with national authorities and partners to ensure all newborns receive evidence-based protection against hepatitis B, and that research in this area adheres to the highest ethical and scientific standards.

Hepatitis B causes hundreds of thousands of deaths globally each year, with transmission at birth being the most common route to chronic infection. In Guinea-Bissau, over 12% of adults are estimated to be living with chronic hepatitis B, and infection rates in children under five are significantly above global targets.