Comparative study on the neurovirulence of different vaccine strains of parotitis virus in monkeys.

The neurovirulence of several mumps virus vaccine strains used for preparation of vaccines in various countries was compared in 44 green monkeys and in 36 Macaca mulatta monkeys. The residual neurovirulence of the attenuated mumps virus strains was demonstrated by morphological examination revealing the specific localization and character of brain lesions after intracerebral (i.c.) administration. We found that the affinity of mumps virus to ependymal cells determines the development of serous meningitis after vaccination with the mumps virus vaccine.