[The immunogenicity of a cultured inactivated hepatitis A vaccine]. / Immunogennost' kul'tural'noi inaktivirovannoi vaktsiny gepatita A.

A trial of inactivated hepatitis A viral vaccine of heteroploid cell culture origin is described. The vaccine preparation was tested in guinea pigs and tamarins. The animals were immunized intramuscularly four or three times, respectively. The efficacy was judged by induction of anti-HAV antibody persisting for at least 12 months in guinea pigs, and development of immunity to subsequent virus challenge (monkeys only). The challenge dose of HAV was unable to produce any signs of HAV infection in the vaccinated tamarins, although the booster effect was observed in some animals. The study demonstrated that the tested batches of the vaccine were highly immunogenic.

[Inactivated vaccine against Japanese encephalitis. The characteristics of a purified preparation from mouse brain]. / Inaktivirovannaia vaktsina protiv iaponskogo éntsefalita. Kharakteristika ochishchennogo preparata iz mozga myshei.

A vaccine has been prepared from formalin-inactivated suspension of brain tissue of Japanese encephalitis (JE) virus-infected white mice. The material was purified by flow ultracentrifugation in sucrose density gradient. Four members of the Nakayama antigenic group were compared as production JE virus strains for the vaccine preparation. Satisfactory results with regard to the immunogenicity of the bulk vaccine determined in mice (the intensity of response and the antigenic spectrum range) were obtained for three of them, including only one of the two variants of the Nakayama NIH strain. The highly purified experimental vaccine proved to be immunologically active and safe in trials in laboratory animals and 20 human volunteers. After two vaccinations, immunological changes in people were recorded much more frequently in the neutralization test than in the hemagglutination-inhibition test. Blasttransformation of lymphocytes in response to the specific antigen was observed in 5 out of 7 vaccines examined. There was no strict correlation of this test with the results of both serological tests.

[Immunological status of people inoculated with various types of inactivated vaccine against tick-borne encephalitis]. / Immunologicheskii status liudei, privitykh razlichnymi tipami inaktivirovannoi vaktsiny protiv kleshchevogo éntsefalita.

As compared with cellular immunity tests, serological tests more frequently detect virus-specific immune response in humans immunized with concentrated purified vaccine (CV) against tick-borne encephalitis. Combined determination of cell reactions and antibody production after a single injection of the vaccine increases the rate of detection of specifically responding persons. The duration of the inactivated vaccine-induced immunity is determined not only by the level of serum antibodies but also by the state of immunological memory detectable by the capacity of the host to produce antibodies after another injection of the specific antigen. At 14 and 30 days after a single immunization with CV IgG antibody is found in the blood of the vaccinees. In the course of 3 vaccinations, the concentration of serum immunoglobulins, chemotaxic activity of leukocytes, and blood lymphocyte reactivity to mitogens do not change. The role of some immunological values as criteria for the evaluation of the effectiveness of vaccine purification from impurities is discussed.

[Concentrated purified vaccine against tick-borne encephalitis. An immunological evaluation in experiments on mice]. / Kontsentrirovannaia, ochishchennaia vaktsina protiv kleshchevogo étsefalita. Immunologicheskaia otsenka v opytakh na myshakh.

Comparative investigations of the immunological activity of two inactivated vaccines against tick-borne encephalitis, concentrated and commercial ones, were carried out. Higher levels of humoral and cellular immune responses were achieved after inoculation of the concentrated vaccine. Both vaccines did not affect the general immunological responsiveness of the animals.

[Immunological indices of human vaccination against tick-borne encephalitis using inactivated preparations with a varying concentration of the viral antigen]. / Immunologicheskie pokazateli vaktsinatsii liudei protiv kleshchevogo éntsefalita inaktivirovannymi preparatami s raznoi kontsentratsiei virusnogo antigena.

The results obtained in the determination of the immunological activity of 3 types of formalin-killed tissue-culture tick-borne encephalitis vaccine, commercial non-concentrated and concentrated by 2 different methods, in humans are presented. Judging by the data of 3 serological tests and the blast transformation test, the concentration of killed tick-borne encephalitis virus enhanced immune response to vaccination. The intensity of this response correlated with the mouse protection capacity of the vaccine batches under test. An increase in the content of viral particles in the preparation is considered to be a promising approach to enhancing the effectiveness of vaccination against tick-borne encephalitis.

[Concentrated purified vaccine against tick-borne encephalitis prepared by means of zonal ultracentrifugation. Development of the preparation]. / Kontsentrirovannaia ochishchennaia vaktsina protiv kleshchevogo éntsefalita, prigotovlennaia metodom zonal'noiogo ul'tratsentrifugirovaniia. Razrabotka preparata.

A concentrated and purified (lyophilized) preparation with a high immunological activity was obtained from formalin-inactivated tissue culture suspensions of tick-borne encephalitis (TBE) virus. Its high immunogenicity was demonstrated in mouse protection tests against fatal challenge with TBE and in the studies of antibody production in monkeys of two species. The preparation was shown to contain no infectious TBE virus, to be safe for small laboratory animals and monkeys. Trials of the preparation in 19 volunteers demonstrated it to be well tolerated and to induce virus-neutralizing antibody production in man. It also sensitized lymphoid cells when inoculated subcutaneously with Al2O3. These experimental materials indicate the possibility of developing a highly potent vaccine against tick-borne encephalitis by concentration and purification of TBE particle suspensions.

[Gel filtration chromatography of tick-borne encephalitis virus on macropore glass]. / Gel'-filtratsionnaia khromatografiia virusa kleshchevogo éntsefalita na makroporistykh steklakh.

The capacity of some chemically treated porous glass to adsorb tissue culture virus of tick-borne encephalitis was studied. Chemical binding of albumin and succinanhydride with the porous glass matrix was found to eliminate virion adsorption on the carrier surface. This permitted to carry out gel filtration chromatography of several virus strains and to obtain highly purified preparations of tick-borne encephalitis virus. Gel filtration on modified porous glass with different pore sizes was used for the determinations of cromatographic radius of virus particle.