The article presents the results of a long-term study of biological and genetic stability of tick-borne encephalitis strain 205 which is used by the FSUE «SPA «Microgen» to produce tick-borne encephalitis vaccines EnceVir (for adults) and EnceVir Neo for children, both of which are tissue cultured, inactivated, purified, and sorbed. The biological stability of strain 205 was studied at the seed lot stage using passages on outbred white mice: initial production strain 205 and production «stock strain». Lyophilisates of production seed lots were studied at different storage intervals at -20 °С (up to 9 years of storage and more). Biological activity parameters (tick-borne encephalitis virus (TBEV) titre in log LD 50 /ml) were studied by using different ways of infecting outbred white mice, and strain 205 identification (specificity) was determined by comparing it to a reference strain in a biological neutralization assay (BNA) according to the manufacturer’s specifications for the vaccines concerned. The same materials and a batch of TBEV vaccine produced from the production «stock strain» (lyophilisate of 1986) were analyzed by polymerase chain reaction (PCR) and sequencing for genetic stability during passaging and long-term storage. The results of the study made it possible to demonstrate the biological and genetic stability of strain 205 during production of TBEV vaccines.

In this research blood serum was tested for specific antibodies so as to investigate the immune system tension in distant periods after the immunization with the tick-borne encephalitis vaccine EnceVir®. It was shown that twelve months after the completion of the initial course of vaccination all the vaccinated adults had specific IgG, with titer rate varying from 1:800 to 1:3200. The retrospective analysis of the vaccines side effects revealed several batches with an elevated number of temperature reactions. Nevertheless, over 80% of the used vaccine batches did not contradict with the EnceVir® instruction manual in terms of the number of side effects.

The article presents the history of the creation and development of Tomsk Bacteriological Institute named after Ivan Churin and Zinaida Churina from the time of its foundation till the present day. The main stages in the development of the scientific trends and production activities of the Institute as well as its role in combating epidemics are shown. The article reveals the contribution of the leading scientists to the development of microbiology and immunobiological drugs manufacture.

Production of the vaccine against the forest-spring encephalitis in the SPS Virion was begun in 1954 on the basis of Sofyin strain. Stages of the vaccine improvement are presented in the article. The vaccine is successfully used in health care.

Inactivated vaccine ОspaVir which was created in the NPO VIRION based upon high immunogenic vaccine virus strain of L-IVP is proved to be safe and having high immunologic activity. The vaccine does not decrease total immunity.