The West African country, one of the region's poorest, has high rates of hepatitis B, and the prospective study had drawn an outcry from scientists and international health bodies because only half the newborns in the trial would get the vaccine at birth. World Health Organization Director-General Tedros Ghebreyesus said it was not ethical.

Guinea-Bissau last month suspended the trial pending an ethical review. Critics had said it was being used to test theories linking vaccines to autism, long promoted by U.S. Health Secretary Robert F. Kennedy Jr but contradicted by scientific evidence.
Foreign Minister Joao Bernardo Vieira said in an interview on Tuesday that the study had been closed, citing concerns raised by the scientific community as well as U.S. senators.   

“It’s not going to happen, period,” he said.
The U.S. Centers for Disease Control and Prevention had approved a $1.6 million grant to fund the study after Kennedy scrapped the agency's recommendation to give the vaccine to all infants at birth in the U.S. 
The American Johns Hopkins University says that about 90% of babies exposed to hepatitis B at birth or in their first year of life develop a chronic infection, and 15% to 25% of these die early of related liver failure or cancer as a result. 

DANISH RESEARCHERS DEFEND U.S.-FUNDED HEPATITIS B TRIAL
The study by researchers at the Guinea-Bissau-based Bandim Health Project, run by the University of Southern Denmark, aimed to enroll 14,000 newborns, specifically to investigate potential "non-specific effects" including skin and neuro-developmental disorders, including autism. 
They note that Guinea-Bissau currently offers the vaccine only at six weeks of age, by which time many infants whose mothers have hepatitis B are already infected. It plans to introduce the dose at birth only in 2028.

Under the trial, half the infants would receive it at birth, the remainder at six weeks, as now.
Frederik Schaltz-Buchholzer, the lead investigator, said the discussion had shifted to politics instead of healthy scientific debate. 
“Everyone will lose if this trial is halted but, especially, confidence in vaccines and health research will suffer greatly,” he said.
He said the group still hoped that a new trial proposal might be accepted in future.
The Bandim project has spent decades in Guinea-Bissau and the researchers say their work aims to better understand the full impact of vaccines, both positive and negative.

Kennedy cited Bandim research to justify cutting U.S. funding to Gavi, a group that helps buy vaccines for the world's poorest countries.

A spokesperson for the U.S. CDC did not respond to a request for comment.
(Editing by Silvia Aloisi and Kevin Liffey)