Researchers at Washington University School of Medicine in St. Louis have identified an antibody that is highly protective at low doses against a wide range of viral variants. Moreover, the antibody attaches to a part of the virus that differs little across the variants, meaning that it is unlikely for resistance to arise at this spot. The findings, available online in the journal Immunity, could be a step toward developing new antibody-based therapies that are less likely to lose their potency as the virus mutates.