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.