Further Studies on the Immunologic Relationships among Measles, Distemper, and Rinderpest Viruses

Abstract

Abstract The reaction between measles and canine distemper viruses prepared in Vero cells and acute, convalescent and hyperimmune sera against these viruses and rinderpest virus were studied in neutralization (NT), neutralization-enhancement (NE), complement-fixation (CF), immunofluorescence, and immunodiffusion tests. In addition, measles virus hemolysis-inhibition (HLI) and hemagglutination-inhibition (HI) tests were carried out with the different sera. The nucleocapsid components of the three viruses could not be distinguished by the immunologic techniques employed. Sera against rinderpest virus contained HLI, HI, and NT antibodies against measles virus. In some sera HLI antibodies were present in marked excess over HI antibodies. NT antibodies against distemper virus were also found in these sera. Sera against distemper virus also displayed measles HLI antibody activity, but no measles virus-specific NT antibodies were detectable. Low titers of HI and NE antibodies were found in some sera. It is concluded that measles, distemper, and rinderpest virus share envelope antigens, which are more readily demonstrated in HLI than in HI tests with measles virus antigen.