From Brigham and Women’s Hospital (L.R.B.), Boston, and Moderna, Cambridge (H.B., R.P., C.K., B.L., W.D., H.Z., S.H., M.I., J. Miller, T.Z.) — both in Massachusetts; Baylor College of Medicine (H.M.E.S.) and Centex Studies (J.S.) — both in Houston; Meridian Clinical Research, Savannah (B.E., S.K., A.B.), and Emory University (N.R.) and Atlanta Clinical Research Center (N.S.), Atlanta — all in Georgia; University of Maryland School of Medicine, Baltimore (K.K., K.N.), and National Institute of Allergy and In