The World Health Organization (WHO) underscores that the hepatitis B birth dose vaccine is an effective, and essential public health intervention, with a proven record. It prevents life‑threatening liver disease by stopping mother‑to‑child transmission at birth. It has been used for over three decades, with more than 115 countries including it in their national schedules. Protecting newborns with a timely birth dose not only provides individual benefit but is also central to national and global elimination efforts.
In response to recent questions from the media, WHO would like to state the following:
WHO is aware of the proposed randomized controlled trial (RCT) on the hepatitis B birth dose vaccine in Guinea‑Bissau. Based on questions raised in publicly available information and consultation with relevant experts, WHO has significant concerns regarding the study's scientific justification, ethical safeguards, and overall alignment with established principles for research involving human participants.
Why withholding the vaccine is unethical
- Proven benefit, foreseeable harm: The hepatitis B birth dose vaccine is known to have a proven safety record across decades of use and is effective in preventing 70–95% of cases of mother‑to‑child transmission. 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, including chronic infection, cirrhosis, and liver cancer.
- 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. Neither condition appears to be met based on publicly available descriptions of the study.
- Insufficient scientific justification: Publicly available descriptions indicate that the protocol does not question the established efficacy and impact of the birth dose; instead, it posits hypothetical safety outcomes without sufficient credible evidence of a safety signal that would warrant exposing participants to risk.
- Biased and low‑utility design: As described publicly, the single‑blind, no‑treatment‑controlled design raises a significant likelihood of substantial risk of bias, limiting interpretability of the study results and their policy relevance.
- Exploiting scarcity is not ethical: Resource constraints cannot be used to justify withholding proven care in a research study involving people. Ethical obligations require minimizing risk and ensuring a prospect of benefit for participants. From what is publicly described, the protocol does not appear to ensure even a minimum level of harm reduction and benefit to the study participants (e.g. screening pregnant women and vaccinating newborns exposed to hepatitis B).
In its current form, and based on publicly available information, the trial is inconsistent with established ethical and scientific principles.
WHO is aware that Guinea-Bissau has suspended the study pending further technical reviews. WHO stands ready to support Guinea‑Bissau as it considers its way forward and in accelerating the introduction of the birth dose and strengthening implementation through:
- birth‑dose delivery within 24 hours (including strategies for home and facility births);
- antenatal screening for hepatitis B surface antigen (HBsAg), linkage to care, and neonatal prophylaxis;
- cold‑chain, last‑mile logistics, and midwife/HCW training; and
- monitoring of timeliness and coverage, pharmacovigilance, and data use for continuous improvement.
WHO remains committed to working with national authorities, researchers, and partners to ensure that all newborns – in Guinea‑Bissau and worldwide – receive timely, evidence‑based protection against hepatitis B, and that research conducted in this area meets the highest ethical and scientific standards.
