Acute viral bronchiolitis : dawn of a new era for the prevention of respiratory syncytial virus infection through vaccination

Abstract

Many cases of bronchiolitis are caused by the respiratory syncytial virus (RSV), which was first identified in 1956 as causing illness in humans. Despite ongoing efforts since the 1960s to develop an RSV vaccine, it has remained elusive. The RSV vaccine research agenda experienced a major setback after the increased susceptibility to severe RSV disease and death in children who received the first formalin-inactivated vaccine in the 1960s. Only in the mid-1980s was the search for an RSV vaccine re-ignited. Alternative approaches to developing this vaccine included attempts at attenuation of RSV, which generally resulted in vaccine candidates that were either too reactogenic or too attenuated. Furthermore, the targeted approach of using the conserved fusion protein (F-protein), although showing some promise in older persons with underlying medical conditions, was not developed into a potential candidate for young children, for whom the need is greatest.