Guinea-Bissau Halts Controversial US-Funded Hepatitis B Vaccine Trial

Guinea-Bissau has permanently halted a controversial hepatitis B vaccine trial after criticism from the World Health Organization and the scientific community. The study, funded by the US CDC, proposed giving only half of 14,000 newborns the vaccine at birth, raising ethical concerns. Authorities said the decision followed international objections and political pressure.

Guinea-Bissau has officially terminated a controversial hepatitis B vaccine trial that had been funded under the administration of former US President Donald Trump, following mounting criticism from global health authorities and members of the scientific community. The decision was confirmed by the country’s foreign minister after weeks of growing international scrutiny and ethical concerns surrounding the design of the study.
The proposed trial had sparked widespread backlash because it planned to enroll approximately 14,000 newborns, with only half of them receiving the hepatitis B vaccine at birth. The remaining infants would have received the vaccine at six weeks, in line with existing local immunization practices. Health experts argued that delaying the birth dose for half of the participants would effectively deny them immediate protection against hepatitis B, a potentially life-threatening infection that can lead to chronic liver disease, cirrhosis, and liver cancer.
Last month, Guinea-Bissau’s authorities suspended the study pending an ethical review amid intensifying criticism. On Tuesday, Foreign Minister Joao Bernardo Vieira confirmed in an interview that the trial had now been definitively closed. He said the government had taken into account objections raised by scientists, international health bodies, and US lawmakers. Emphasizing the finality of the decision, he stated, “It’s not going to happen, period.”
The trial had been backed by a $1.6 million grant approved by the Centers for Disease Control and Prevention. It was to be conducted by researchers affiliated with the Bandim Health Project, an established research initiative based in Guinea-Bissau and operated by the University of Southern Denmark. According to the researchers, the study aimed to explore potential “non-specific effects” of the hepatitis B vaccine beyond its primary purpose of preventing infection. These included possible impacts on skin conditions and neurodevelopmental outcomes, including autism.
However, critics expressed alarm that the trial appeared to align with long-debated and scientifically discredited claims linking vaccines to autism. Such theories have been repeatedly refuted by extensive global research. The issue became more politically charged because similar claims have been publicly promoted in the past by US Health Secretary Robert F. Kennedy Jr., despite overwhelming scientific consensus rejecting any causal connection between vaccines and autism.
The World Health Organization strongly criticized the trial’s design, stating that withholding a proven, life-saving intervention from a portion of newborns could expose them to “potentially irreversible harm.” The agency reaffirmed that the hepatitis B birth dose vaccine is considered an “effective and essential” public health measure, with a long-standing record of safety and effectiveness in preventing mother-to-child transmission of the virus.
Frederik Schaltz-Buchholzer, the study’s lead investigator, defended the scientific intentions behind the research, arguing that the debate had shifted from constructive scientific dialogue to political controversy. He warned that canceling the trial could have broader implications for confidence in vaccines and health research. Nevertheless, he indicated that the research team hopes to revise the proposal and possibly resubmit a modified version for consideration in the future.
The Bandim Health Project, which has conducted health research in Guinea-Bissau for decades, maintains that its work is focused on gaining a deeper understanding of vaccines’ overall effects on child health, both direct and indirect. Despite the closure of this particular study, the episode has highlighted the delicate balance between advancing medical research and upholding strict ethical standards, especially when vulnerable populations such as newborns are involved.