Related Experiment Video
Updated: Sep 6, 2026

Intranasal Administration of Recombinant Influenza Vaccines in Chimeric Mouse Models to Study Mucosal Immunity
Published on: June 25, 2015
A cold-adapted mutant of parainfluenza virus type 3 is attenuated and protective in chimpanzees
S L Hall1, C M Sarris, E L Tierney
1Respiratory Viruses Section, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892.
Abstract:
A live attenuated cold-adapted parainfluenza virus type 3 (PIV-3) vaccine is being developed to prevent the serious lower respiratory tract disease caused by this virus in infants and young children. This cold-passaged mutant (cp45) was evaluated in seronegative chimpanzees and found to be highly attenuated in both the upper and lower respiratory tracts compared to its wild-type parent. Animals immunized with cp45 were also highly resistant to wild-type PIV-3 challenge. Stability of the attenuation phenotype was demonstrated by the administration to 2 additional chimpanzees of an isolate of cp45 obtained after 10 days of replication in a chimpanzee. It was attenuated in both the upper and lower respiratory tracts. The cp45 virus present in the respiratory tract secretions of chimpanzees retained the temperature-sensitive (ts) phenotype, but some loss of ts property was observed in the isolates. These results provide a basis on which to proceed to clinical trials in seronegative human infants and children.
Related Concept Videos
Viral Recombination
Viral Mutations
Influenza

