title: Laboratory markers for over-attenuation of mumps vaccine virus.
abstract: The properties of mumps vaccine virus (Leningrad-3 strain) gradually changed upon passaging in quail embryo fibroblasts, the substrate normally used for mumps vaccine production in the USSR. Alterations were extremely noticeable in the over-attenuated (38th passage) virus variant, and involved (a) poor, if any, antibody response in guinea-pigs, (b) turbid plaque formation, (c) lack of expression in cell culture of fusion protein and reduced expression of polymerase protein, and (d) enrichment by abnormally small, fusion-protein-deficient virus particles. Two other laboratory strains exhibited a similar trend to over-attenuation, though after variable passage numbers. Due to a good inter-correlation, every test (namely, inoculation of guinea-pigs, plaque assay, protein analysis, or immune electron microscopy) is indicative of mumps vaccine over-attenuation and hence might be valuable in seed virus quality control.
authors.affiliation: Institute for Viral Preparations, Moscow, USSR.
authors.lastname: Boriskin YuS
authors.forename: T I
authors.initials: TI
authors.lastname: Kaptsova
authors.forename: V D
authors.initials: VD
authors.lastname: Lotte
authors.forename: O I
authors.initials: OI
authors.lastname: Skvortsova
authors.forename: C
authors.initials: C
authors.lastname: Orvell
mesh_terms: D000818:Animals; D000937:Antigen-Antibody Reactions; D015415:Biomarkers; D006168:Guinea Pigs; D009109:Mumps virus / Q000276:immunology*; D010316:Particle Size; D014613:Vaccines, Attenuated / Q000032:analysis; D014760:Viral Fusion Proteins; D010948:Viral Plaque Assay; D014765:Viral Vaccines / Q000032:analysis
chemical_list: D015415:Biomarkers; D014613:Vaccines, Attenuated; D014760:Viral Fusion Proteins; D014765:Viral Vaccines