title: Non-protective variants of Marek's disease vaccine viruses.
abstract: Two variant Marek's disease-vaccine viruses failed to induce protective immune responses in chickens and replicated poorly in vivo. One of these, MDV/200D, was defective for growth at 41 degrees C, and clones from this stock had 38 degrees C/41 degrees C plating ratios as high as 10(4). The basis for the poor in vivo replicative ability was not determined.
mesh_terms: D000818:Animals; D002645:Chickens; D003673:Defective Viruses / Q000276:immunology; D006564:Herpesviridae / Q000276:immunology; D008381:Herpesvirus 2, Gallid / Q000276:immunology*; D008380:Marek Disease / Q000517:prevention & control*; D013696:Temperature; D014422:Turkeys; D014765:Viral Vaccines / Q000302:isolation & purification* / Q000494:pharmacology
chemical_list: D014765:Viral Vaccines