title: Immunosuppressive effect of infectious bursal disease virus strains of variable virulence for chickens.
abstract: Infection of chicks with attenuated Lp and Sp clones of the RF-1 strain of infectious bursal disease virus was shown to exert no immunosuppressive effect, whereas the parent strain RF-1tc and the original virulent strain RF-1wt were immunosuppressive. One-day-old chicks infected with Lp and Sp clones showed no suppression of immunological response to live Newcastle disease vaccines B1 and TCND, and to bivalent infectious coryza vaccine. On the other hand, infection with RF-1tc or RF-1wt strains was immunosuppressive for these vaccines. The immunosuppressive effect of RF-1tc and RF-1wt strains was more pronounced for infectious coryza vaccine and B1 vaccine than for TCND vaccine. The immunosuppressive effect of RF-1tc and RF-1wt strains was lower when chicks were infected with these strains at the age of 21 days than when they were infected at one day of age.
authors.affiliation: Research Center for Veterinary Science, Kitasato Institute, Chiba, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Higashihara
authors.forename: K
authors.initials: K
authors.lastname: Saijo
authors.forename: Y
authors.initials: Y
authors.lastname: Fujisaki
authors.forename: M
authors.initials: M
authors.lastname: Matumoto
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000096:biosynthesis; D001835:Body Weight; D002060:Bursa of Fabricius / Q000473:pathology; D002478:Cells, Cultured; D002642:Chick Embryo; D002645:Chickens; D006385:Hemagglutination Inhibition Tests; D007108:Immune Tolerance; D007243:Infectious bursal disease virus / Q000276:immunology* / Q000472:pathogenicity; D009929:Organ Size; D011201:Poultry Diseases / Q000276:immunology* / Q000382:microbiology; D012088:Reoviridae Infections / Q000276:immunology / Q000382:microbiology / Q000662:veterinary*; D013047:Specific Pathogen-Free Organisms; D014613:Vaccines, Attenuated / Q000276:immunology; D014765:Viral Vaccines / Q000276:immunology; D014774:Virulence
chemical_list: D000914:Antibodies, Viral; D014613:Vaccines, Attenuated; D014765:Viral Vaccines