Scientists have taken a major step toward stopping Epstein-Barr virus (EBV), an extremely common infection linked to cancer and chronic disease. By using mice engineered with human antibody genes, researchers created powerful human-like antibodies that block the virus from attaching to and entering immune cells. One of these antibodies completely prevented infection in lab models with human immune systems, marking a breakthrough after years of difficulty tackling EBV’s ability to invade nearly all B cells.