Influenza and Respiratory Syncytial Virus (RSV) infections are the two most common respiratory viral pathogens causing increased morbidity and mortality. For over 30 years, the University of Rochester has been one of the leading institutions studying human respiratory viral infections with Caroline B Hall, John Treanor, Edward E Walsh, and Ann R Falsey. Earlier work by CB Hall, and recent work by EE Walsh, and AR Falsey established RSV infections as a major cause of morbidity and mortality in young infants and elderly patients. Despite universal infection by age 3, repeat RSV infections during adulthood are quite common suggesting immunity is partial at best. Moreover, the host viral immune response is important in clearance of these viruses; however, it may also contribute to the pathology of severe lung disease. Currently there is no vaccine for RSV; there are only vaccines to influenza.