The Trump administration, under Health Secretary Robert F Kennedy Jr, will fund a $1.6 million study on hepatitis B vaccination in newborns in Guinea-Bissau. Nearly 20% of adults in Guinea-Bissau live with hepatitis B, a serious liver virus. The US CDC recently changed recommendations, making the hepatitis B vaccine at birth an “individual” choice, abandoning decades of safe and effective policy. Researchers and health experts call the study “highly unethical” and “extremely risky.” The study will test newborns with or without the hepatitis B vaccine to compare health effects over five years. This is controversial because the World Health Organization recommends all babies get the birth dose, and withholding it is considered unethical. Paul Offit, a vaccine expert at Children’s Hospital of Philadelphia, said, "It’s highly unethical to choose to give a vaccine to some children but not others." Elizabeth Jacobs of the University of Arizona warned the study’s impact spreads "like an infection all its own throughout the globe." The study is led by Danish researchers Peter Aaby and Christine Stabell Benn, who have been criticized for past questionable research. Their new work, funded by the US, will take place in Guinea-Bissau’s fragile health system. Experts like Gavin Yamey of Duke University see this as a "neocolonialist attitude" that risks increasing mistrust of science. Kennedy, known as a longtime anti-vaccine activist, has cut US funding for global vaccine programs, including Gavi, which saved millions of lives worldwide. He cited a discredited 2018 study to justify ending support but ignored a 2022 study that contradicted those claims. Most experts agree efforts should focus on increasing birth-dose coverage, not testing vaccine safety again. Andrew Pollard of Oxford said the priority is to protect babies, noting only 17% of African newborns currently receive the vaccine at birth. The study’s design is also questioned. It is single-blinded, meaning researchers know who did or didn’t get vaccinated, risking bias. Endpoints are vague “overall health effects,” making the results unclear and open to interpretation. Martin McKee of London School of Hygiene calls the study "a policy desperately searching for evidence" and worries about informed consent in a vulnerable population. Critics warn Robert F Kennedy Jr may misuse the study to reinforce his anti-vaccine stance, despite strong evidence vaccines save lives. Paul Offit said, "It’s hard to sleep knowing that children are constantly being put in harm’s way by the administration." The global health community watches closely as children’s futures are at stake.