[Properties of rubella virus persisting in cultures of human cells]

Comparative studies showed rubella virus persisting in chronically infected HEp-2-BK cell culture not to differ significantly from the original strain in the cytopathic effect in RK-13 and BHK-21/13S cells, the interfering capacity with heterologous viruses, and hemagglutinating properties, but to form smaller plaques. The persisting variant and the original virus had low sensitivity to heating at 56 degree C for 10 min. Reproduction of both viruses in RK-13 and BHK-21/32S cell cultures was slightly lower at 40 degree and 36 degree C. At the same time, virus replication in chronically infected cells was not temperature-dependent. The virus variants were shown to be completely antigenically identical by cross-neutralization tests, plaque production, and hemagglutination-inhibition with strain-specific sera.