title: The antigenicity and immunogenicity of the intracellular and extracellular forms of vaccinia virus. I: The production of high-titre vaccinia extracellular virus and its antigenicity after inactivation.
abstract: Vaccinia extracellular virus, which until recently (Payne, 1979) had only been produced at low titre, 10(5)-10(6) pfu/ml, was produced at titres of up to 10(7.5) pfu/ml by selective combination of virus, cell and medium. It could be concentrated to 10(9)-10(9.3) pfu/ml by ultrafiltration without significant losses in quantity or quality. The final preparation was only contaminated to the extent of 25-50% with virus neutralizable by antiserum to intracellular virus, compared with the 70-90% found by other workers. When inactivated it produced good antibody titres in rabbits. In contrast, mice failed to produce antibody to extracellular virus, but did so to intracellular virus: they were also protected against a potentially lethal challenge with ectromelia virus.
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000096:biosynthesis*; D000956:Antigens, Viral / Q000276:immunology; D004482:Ectromelia, Infectious / Q000517:prevention & control; D051379:Mice; D008808:Mice, Inbred CBA; D009500:Neutralization Tests; D011420:Propiolactone / Q000494:pharmacology; D011817:Rabbits; D014616:Vaccinia virus / Q000187:drug effects / Q000276:immunology*; D014765:Viral Vaccines / Q000302:isolation & purification
chemical_list: D000914:Antibodies, Viral; D000956:Antigens, Viral; D014765:Viral Vaccines; D011420:Propiolactone