RSV (Respiratory syncytial virus) is a leading cause of acute respiratory infections. RSV can exploit host immunity and cause a strong inflammatory response that leads to lung damage and virus dissemination. There is a single RSV serotype with two major antigenic subgroups, A and B.
RSV is a non-segmented negative-sense single-stranded enveloped RNA virus that belongs to the family of Paramyxoviridae, genus Pneumovirus, subfamily Pneumovirinae. Its 10 genes encode 11 proteins since two overlapping open reading frames in the M2 mRNA yield two distinct matrix proteins, M2-1 and M2-2. The viral envelope contains three proteins, the G glycoprotein, the fusion (F) glycoprotein, and the small hydrophobic (SH) protein. The RSV virus comprises five other structural proteins, the large (L) protein, nucleocapsid (N), phosphoprotein (P), matrix (M), and M2-1, and two non-structural proteins (NS1 and NS2).