[Comparative study of the viremia in tick-borne encephalitis in immune and nonimmune animals].

A long-term viremia (12 days postinoculation, the observation period) of both cellular and plasma type was detected in mice experimentally infected with tick-borne encephalitis virus, the Sophyin strain. Preliminary vaccination was found to prevent viremia in experimentally infected animals. Comparative studies of cellular and humoral immune responses in vaccinated mice showed the cellular immune responses to be most important in eliminating the virus upon subsequent experimental inoculation of mice with tick-borne encephalitis virus.