Vol 49, No 5 (2004)

Nucleotide sequences of the VP1 genome of 28 ECHO 30 strains isolated in 1998-2002 in Russia and several CIS countries were determined. The EV30 studies strain were divided into 4 groups according to isolation place and time. Group 1 is presented by 2 strains isolated in 1998 in Russia and Byelorussia. Group 2 comprises 17 strains isolated in 1999- 2000 in Russia (its southern regions and Stavropol Territory), Ukraine, Georgia, and Azerbaijan. Five strains isolated in 2002 in Russia (Kalmykia) belong to Group 3; and Group 4 has 4 strains isolated in 2002 in Moldova and Russia (Magadan). A frequently changing EV30 subtype was simultaneously detected in extensive territories.

The reactogenicity of the embryonic live recombinant variola and hepatitis В bivaccine as tablets (Revax-BT) as well as its safety and immunogenicity were evaluated in clinical trials made in volunteers who had previously immunized or not with variola vaccine. A preliminary conclusion was made on a lack of side effects and drug safety in primary vaccination and been revaccination with low and high doses. Primary immunization of volunteers and as bivaccination with high doses stimulated the most pronounced immune response to the vaccine virus versus such effect observed in immunization of volunteers with low vaccine doses. Humoral immune response to HBs was observed in 75% of volunteers of both groups after as bivaccination. Such response was most pronounced in examinees immunized with low vaccine doses versus those who received high bivaccine doses. At the same time, no protective levels of humoral immunity response to HBs Ag were observed in volunteers first vaccinated.

The morbidity structure was analyzed in children vaccinated against epidemic parotitis in 1993-2002. Eight children (4 with serous meningitis and 4 with lesions of the salivary glands) underwent virologic and immunologic examinations. The molecular typing of the SH-gene fragment of the parotitis virus showed the process in 7 cases to be provoked by the vaccination strain. Presumedly, progressing vaccine-associated meningitis inhibits antibody formation. The total incidence of vaccine-associated meningitis was shown, according to Saint Petersburg data, to be not high, which testifies to a low reactogenicity of the Russian vaccine strain.

The conducted studies showed a certain efficiency of gene-engineering preparation of IFN-y and TNF-T in virus infections caused by herpes simplex virus 2 (HSV-2) and cytomegalovirus (CMV) in cell cultures of human embryo fibroblast (HEF). The drugs have no viricidal action. IFN-y, when used according to the treatment scheme in vitro, proved to be more effective versus TMF-T both in HSV-2 and in CMV. It inhibited significantly the HSV-2 reproduction within the dilution range of 1: 50 to 1 : 500. It was also effective, when used in CMV, within the dilution range of 1 : 5000 and lower, whereas TNF-T was effective within the range of 1 : 500 and lower as well as in 0.1 multiple infection. A significantly higher effect was ensured when the drugs were used for prevention. In HSV-2, IFN-y inhibited the virus reproduction, like in the treatment scheme, within the dilution range of 1 : 50 to 1 : 500, whereas TNF-T was effective in the range of 1 : 50. In CMV, the drugs' effect, when used for prevention, was similar to that observed in the treatment scheme. The highest inhibition values were registered for HSV-2, when it was used 24 hours before infection (IFN-y - 2.25 lg, dilution range of 1 : 50; TNF-2 -1.0 lg, dilution range of 1 : 50). IFN-y and TNF-2 exert a synergic action on different stages of virus reproduction. A reliable additive effect was ensured in prevention made 4 hour before infection by IFN-y and TNF-T only in experimental CMV infection.

A study was undertaken to prove that a vaccine drug based on the fast- growing MB-7 (MB-7 VD) of hepatitis A virus (HAV) is safe. It was established that MB-7 VD, when once injected to white outbred mice and when 4 times injected to Hartley guineas pigs, did not cause any hematological and biochemical changes in the peripheral blood or in the condition of the central nervous system of experimental animals, which shows that MB-7 VD is free of any toxic properties.