Suppression of cell-mediated immunity after infection with attenuated rubella virus.

The effects of attenuated rubella virus infection upon cell-mediated immunity of human volunteers were studied. The volunteers received the vaccine either by nose drops or by the subcutaneous route. Changes in cell-mediated immunity in terms of delayed cutaneous sensitivity to recall antigens, phytohemagglutination stimulation, and spontaneous migration inhibitory factor-like activity were studied at various time periods after infection. Spontaneous migration inhibitory factor-like activity was studied on supernatants of the lymphocytes obtained from the volunteers and incubated for 72 h in the absence of any antigens. A significant proportion of the volunteers showed suppression of one or more parameters of cell-medicated immunity tested by week 2 of infection compared to the control; however, there was no correlation between suppression of the various parameters studied. No difference was noticed in the incidence of cell-mediated immunity suppression between nose drops and subcutaneous route groups.