1. From the Division of Maternal Fetal Medicine, Department of Gynecology and Obstetrics, and the Division of Clinical Pharmacology, Johns Hopkins University School of Medicine, Baltimore (A.C.E.); the Department of Pediatrics, Boston University Chobanian & Avedisian School of Medicine (M.M.), the Division of Infectious Diseases, Brigham and Women’s Hospital (S.L.), and the Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health (S.L.) — all in Boston; and the Botswana...