[Vaccination against tick-borne encephalitis in the Central Slovakia Region using a Soviet vaccine].

During the period between 1986 and 1989 in the region 1311 people working in forestry were vaccinated against tick-borne encephalitis by the inactivated Soviet vaccine. Only some of the people had prevaccination examinations only in some reactogenity of the vaccine was investigated as well as the persistence of humoral antibodies one and two years after the basic vaccination. These examinations in some of the vaccinated subjects were made in autumn 1986 and spring 1987. After two doses of vaccine in the haemagglutination-inhibition test (HIT) the seroconversion was 77% (of 182 evaluated) with a geometric mean of 37.9. One year after the primary vaccination in 53% of the examined subjects the titre of humoral antibodies dropped to negative values. Two years after the primary vaccination in the HIT antibodies were detected in 44% of 57 examined subjects. None of the immunized subjects contracted tick-borne encephalitis.