The parameters of nonspecific immunity (interferon, tumor necrosis met
er, natural killers), of spontaneous and mitogen-induced lymphocyte pr
oliferation, of specific immunity (antibodies to Marburg virus, antige
n-stimulated proliferation) were found to change in the course of expe
rimental Marburg fever in immune and intact animals. The named factors
were shown to influence the course of the disease; their role in the
lethal outcome of the infection was demonstrated.