Two genetically modified broadly neutralizing antibodies (bNAbs) protected rhesus macaques from an HIV-like virus, report scientists. After introducing genetic mutations into two potent HIV bNAbs, researchers prepared intravenous infusions of two bNAbs. Single infusions of each modified bNAb protected monkeys against weekly exposures to simian-human immunodeficiency virus (SHIV) up to 37 weeks, compared with a median of three weeks in 12 monkeys receiving no antibody.