title: Biological characteristics of Marek's disease vaccine CVI-988 clone C1.
abstract: Biological characteristics of Marek's disease virus (MDV) CVI-988 clone C, of importance for vaccine application, are described. CVI-988 clone C was shown to be nonpathogenic for highly MD-susceptible chickens and slightly more effective than prototype CVI-988 vaccine. During plaque purification and serial cell-culture passages, reductions were observed in the release of 'A' antigen from infected cell cultures, in spreading properties and in virus replication in vivo. Pre-licensing batches of CVI-988 clone C vaccine afforded excellent protection against challenge infection with virulent MDV and highly virulent MDV strains. Groups of chickens with bivalent (HVT/SB-1) vaccine-induced maternal antibodies were equally protected by a double dose of CVI-988 clone C vaccine. Field trials performed in the Netherlands and in the United States confirmed the safety and protective efficacy of monovalent CVI-988 clone C vaccine.
authors.affiliation: Central Veterinary Institute, Virology Department, Lelystad, The Netherlands.
authors.forename: G F
authors.initials: GF
authors.lastname: de Boer
authors.forename: J M
authors.initials: JM
authors.lastname: Pol
authors.forename: H L
authors.initials: HL
authors.lastname: Oei
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000096:biosynthesis; D002645:Chickens; D005455:Fluorescent Antibody Technique; D008381:Herpesvirus 2, Gallid / Q000276:immunology*; D008380:Marek Disease / Q000517:prevention & control*; D013047:Specific Pathogen-Free Organisms; D014613:Vaccines, Attenuated / Q000009:adverse effects / Q000276:immunology / Q000592:standards; D014765:Viral Vaccines / Q000009:adverse effects / Q000276:immunology / Q000592:standards
chemical_list: D000914:Antibodies, Viral; D014613:Vaccines, Attenuated; D014765:Viral Vaccines