[Reactogenicity and immunological effectiveness of a concentrated, purified vaccine against tick-borne encephalitis].

Human reactogenicity and immunological efficacy of concentrated purified tick-borne encephalitis (CTBEV) vaccine was studied in a controlled trial. The new vaccine was found to be superior to the commercial preparation in its capacity to induce specific humoral and cell-mediated immunity in man and in reduced sensitizing activity with regard to nonviral cellular antigens. Two vaccinations with CTBEV in doses of 0.5 ml each at 6-month interval are recommended. At this vaccination schedule virus neutralizing antibodies were detectable in 95% vaccines. Inoculation of 0.5 ml CTBEV is accompanied by fever of mild and moderate intensity in 19% and 3% of the vaccines, respectively. In this respect CTBEV is less reactogenic than the commercial preparation.