The World Health Organization acknowledged that some observational studies have raised questions about prenatal exposure to acetaminophen and developmental outcomes. But the UN agency also noted that the overall evidence is inconsistent—some studies see hints of an association, others find none. Since then, multiple large-scale studies—some looking at hundreds of thousands of children—have found no causal link between vaccines and autism. When leaders question well-established advice, it undermines years of public health work.”At a suburban clinic in Lagos, a pharmacist named Chima described a more practical fear. It remains one of the most contagious human diseases; public health experts warn that drops in vaccination coverage can lead to resurgences.