Rubella Virus

Abstract

Summary

The developments of infectious virus (extracellular and intracellular) and the specific CF antigen of rubella virus were studied in a continuous line of rabbit kidney tissue culture cells. The thermal stability and effect of ultraviolet irradiation on the virus and the CF antigen were also examined. During initial virus synthesis, intracellular infec-tivity titers were consistently higher than the extracellular titers. Intracellular infectivity reached a peak titer of 6.8 log₁₀/0.1 ml at 48 hours after infection, after which it fell slightly and leveled off. Extracellular virus infectivity did not reach its peak titer of 5.8 log₁₀/0.1 ml until 12 hours after infection, and remained stable until termination of the experiment. Rubella CF antigen was first detected 48 hours after infection and reached a maximum titer at 72 hours, followed by a sharp decrease. This decrease in titer was attributed to a probable stop in synthesis of the antigen by the infected cells, and thermal in-activation. Thermal and UV inactivation of virus infectivity followed the expression of a first order reaction. The CF antigen was thermo-labile at 34°C, and its inactivation was also exponential; the antigen was, however, stable to ultraviolet irradiation up to 30 minutes exposure.