title: Influence of natural exposure on response to subsequent challenge with virulent Marek's disease virus.
mesh_terms: D000005:Abdomen; D000818:Animals; D001353:Avian Leukosis / Q000276:immunology*; D002645:Chickens / Q000276:immunology*; D006564:Herpesviridae / Q000276:immunology* / Q000472:pathogenicity; D007110:Immunity, Active; D005779:Immunodiffusion; D007267:Injections; D008722:Methods; D010523:Peripheral Nervous System Diseases / Q000276:immunology; D011201:Poultry Diseases / Q000276:immunology*; D013997:Time Factors; D014774:Virulence