Respiratory syncytial virus (RSV) is a highly contagious pathogen of the respiratory tract, primarily in infants and the elderly. A vaccine against RSV is currently not available, but is desired due to the high disease burden.RSV has two major surface glycoproteins (G and F) that play important roles in the initial stages of the infectious cycle. The RSV G protein is a glycosylated membrane protein that has an extracellular ectodomain, containing a central conserved domain (CCD) with four cysteine residues that are highly conserved in all RSV isolates. This central conserved domain (CCD) contains a CX3C chemokine motif (amino acids 182–186) that facilitates RSV attachment to susceptible cells bearing a CX3C chemokine receptor, CX3CR1. The G protein mediates attachment of the virus to the host cell membrane by interacting with heparan sulfate, initiating the infection. The G protein mediates attachment of the virus to the host cell membrane by interacting with heparan sulfate, initiating the infection. Secreted glycoprotein G helps RSV escape antibody-dependent restriction of replication by acting as an antigen decoy and by modulating the activity of leukocytes bearing Fcgamma receptors. Unlike the other paramyxovirus attachment proteins, HRSV-G lacks both neuraminidase and hemagglutinating activities.