[Vaccines based on the Far-Eastern and European strains induce the neutralizing antibodies against all known tick-borne encephalitis virus subtypes].

Serum of children aged 1 to 16 obtained in the course of clinical trials conducted in the sverdlovsk region in 2011 was used to study the post-vaccination immunity. Children were immunized twice with vaccines against the tick-borne encephalitis (TBE) Tick-E-Vak on the basis of the strain sofjin of the Far-Eastern subtype and FSME-IMMUN Junior based on the neudorfl strain of the european subtype. According to the plaque reduction neutralization test (PRNT), both vaccines have a high immunogenicity: after 30 days since two-time vaccination in the sera of 100% of children immunized with the vaccine Tick-E-Vak and in the 95% of children immunized with the vaccine FSME-IMMUN Junior antibodies (AT) against strain sofjin were identified in protective titers, whereas 24.5% and 21.4% of children, respectively, had antibody titers higher than 1:10000. selected sera of recipients with titers from 1:25 to 1:1000 were examined in the PRNT in a single experiment using the sofjin (Far-Eastern subtype), absettarov (European subtype) and Vasilchenko (Siberian subtype) strains. The two vaccines induced AT against the representatives of all three subtypes.