DEVELOPMENT OF A NOVEL SUBUNIT VACCINE THAT PROTECTS COTTON RATS AGAINST BOTH HUMAN RESPIRATORY SYNCYTIAL VIRUS AND HUMAN PARAINFLUENZA VIRUS TYPE-3

A cotton rat model of experimental human respiratory syncytial virus ( RSV) and human parainfluenza virus type 3 (PIV-3) infection was used t o examine the efficacy of F(R)HN(P), a novel chimeric glycoprotein whi ch contains the extracellular regions of the fusion glycoprotein of RS V and the attachment glycoprotein of PIV-3, as a single subunit vaccin e against these two viruses. This work was prompted by previous cotton rat studies that demonstrated that the major protective antigens of t he two viruses were these glycoproteins. F(R)HN(P) was expressed in in sect cells using a recombinant baculovirus. Vaccination with F(R)HN(P) resulted in induction of both RSV and PIV-3 neutralizing antibody and doses of 200 ng completely protected rats from either RSV or PIV-3 ch allenge. These results demonstrate that in the cotton rat animal model a single chimeric glycoprotein can be an effective vaccine against bo th RSV and PIV-3.