Vim Research, zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCB ll(l988) 1-15 Elsevier VRR 00429 zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA Review Article Current approaches to the development of vaccines effective against parainfluenza and respiratory syncytial viruses Brian R. Murphy ‘, Gregory A. Prince 2, Peter L. Collins ‘, Kathleen Van Wyke Coelingh I, Robert A. Olmsted ‘, Melanie K. Spriggs ‘, Robert H. Parrott 3, Hyun-Wha Kim 3, Carl D. Brandt 3 and Robert M. Chanock 1 ’ Laboratory of Infectious Diseases, Nationai Insiitute of AliergV and Infectious Diseases, National Institutes of Health, Bethesda, Maryland U.S.A.; 2 Johns Hopkins University, Baltimore, Maryland U.S.A.; 3 Children’s Hospital, National Medical Center, Washington, D.C., U.S.A. (Accepted for publication 15 March 1988) Summary Vaccines against parainfluenza (PIV) and respiratory syncytial viruses (RSV) that are currently being developed include both live and subunit vaccines. Candidate live PIV vaccines that have been found to be attenuated and efficacious in rodents or primate models are (1) cold-adapted, temperature-sensitive mutants of PIV-type 3 that have been serially passaged at low temperature (20 o C) in simian kidney tissue culture; (2) protease-activation mutants (PIV-1-Sendai), which have mutations that decrease the cleavability of their F glycoprotein by host cell protease; (3) an animal virus, bovine PIV-3 virus, which is antige~c~ly related to the human PIV-3 virus, and (4) vaccinia recombinant viruses bearing RSV or PIV-3 glycoproteins. Subunit RSV and PIV-3 viruses are being produced and evaluated as immuno- gens. A major concern with these vaccines is the possibility of disease potentiation following virus infection as occurred previously with formal&inactivated measles and RSV vaccines. Studies indicate that PIV-3 and RSV gly~oprotein vaccines are immunogenic and efficacious in animals but insufficient data exist to estimate their capacity to potentiate disease. However, since a cotton rat model is available to detect potentiated disease resulting from infection of cotton rats previously im- Co~~~ondence ro: Brian R. Mushy, Laboratory of Infectious Diseases, NationaI Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, U.S.A. Tel. (301) 496-4205.