Abstract
In accompanying papers (P. L. Acosta, M. T. Caballero, and F. P. Polack, Clin Vaccine Immunol 23:189-195, 2016, http://dx.doi.org/10.1128/CVI.00609-15; M. Vissers, I. M. L. Ahout, M. I. de Jonge, and G. Ferwerda, Clin Vaccine Immunol 23:243-245, 2016, http://dx.doi.org/10.1128/CVI.00590-15) in this issue of Clinical and Vaccine Immunology, the history of and immune mechanisms underlying vaccine-enhanced respiratory syncytial virus (RSV) disease and of investigations of mucosal antibodies and their association with viral load in RSV-infected children, respectively, are described. This commentary discusses RSV vaccine candidates, target populations, and the challenges associated with achieving a safe and effective vaccine.