Protection of cotton rats against human respiratory syncytial virus by vaccination with a novel chimeric FG glycoprotein.

The cotton rat model of experimental human respiratory syncytial virus (RSV) infection was used to study the efficacy of FG, a novel chimeric glycoprotein which was expressed in insect cells using a baculovirus vector. FG contained the extracellular regions of the F (fusion) and G (attachment) glycoproteins of RSV. Vaccination with FG resulted in induction of neutralizing antibody and was correlated with protection of lung tissue from RSV challenge against both serogroup A and B virus strains. Both crude FG taken from supernatants of insect cells and affinity-purified FG were immunogenic and active against RSV. FG vaccination was effective by three routes of administration, following a single dose, and when administered with different adjuvants.