Vol 55, No 3 (2010)

The paper describes the trend in the spread of pandemic influenza A(H1N1) swl virus in the Far East, which started in this region 2-3 months later than that in the European part of Russia. By mid-October seasonal epidemic influenza was practically displaced by pandemic one.

The study of the antiviral activity of Russian anti-influenza agents in the cultured MDCK cells demonstrated that arbidol and ribavirin inhibited the reproduction of various influenza A virus strains, including rimantadine- and ozeltamivir-resistant variants, as well as influenza B viruses (IC50 2-8.5 μg/ml). Rimantadine at concentrations of 1-5 μg/ml completely inhibited the reproduction of reference and ozeltamivir-resistant influenza A virus strains, and it had no effect on the reproduction of influenza B viruses and rimantadine-resistant influenza A viruses. Arbidol and ribavirin also inhibited the reproduction of pandemic influenza A/California/04/2009(H1N1), A/California/07/2009(H1N1), and A/Moscow/01/2009(H1N1)swl viruses in the cultured MDCK cells (IC50 = 1.5-4.0 μg/ml) while rimantadine had no effect on their reproduction. The cultured cells showed no significant antiviral activity of ingavirin at nontoxic concentrations (up to 200 μg/ml) against all study strains of influenza A and B viruses, including pandemic A(H1N1) influenza virus strains. The activity of rimantadine, arbidol, and ingavirin was found on a model of influenza pneumonia in mice infected with their adopted influenza A/Aichi/2/69(H3N2) virus. The preventive efficacy of the three test agents was similar and most pronounced when they were used 96 hours before infection, by preventing 40-50% death in the animals and their body weight loss and by increasing their survival by 1.3-1.5 times. Arbidol and rimantadine were more effective when used for treatment and prophylaxis in doses of 30 and 10 mg/kg/day, respectively, by protecting the infected animals from 60-80% death, increasing their survival by 1.7-2 times, and preventing their body weight loss as compared with the control. The same experiments with ingavirin showed that this agent was less effective than arbidol and rimantadine. Thus, arbidol and rimantadine have a pronounced antiviral infection in both cell culture and a model of influenza pneumonia. The found efficacy of ingavirin on an integral model of murine influenza pneumonia without its activity in the cultured cells is likely to be due to other pharmacological properties of the drug rather than its direct virus-specific action.

The paper shows variability of the functional activity of the superficial structures of three Far Eastern strains of tick-borne encephalitis (TBE) virus used to study the immunogenicity of different vaccines. The avidity antibodies to the study TBE virus strains were not detected in all of the persons vaccinated with different TBE vaccines even in the year of immunization. Two years after a course of vaccination, immune response and antibody avidity were decreased in the vaccinees. The persons vaccinated with "eastern" vaccines were better protected against Sofjin-like strain P-73 that had led to a fatal outcome in a patient with TBE. Those vaccinated with "western" strain vaccines were found to have a higher affinity for antibodies to the strains P-202 and P-69 that caused inapparent TBE in the year of immunization and 2 years later. A group of persons vaccinated with both "western" and "eastern" vaccines in different periods showed rather high antibody avidities.

Five phosphodipeptides were synthesized; two of them (H-Lys-Ala(P) and H-Pro-Ala(P)) had interferon-induced activity. These dipeptides at millimolar concentrations (10-4 and 10-5 M) induced the synthesis of late (40-hour) interferon in human peripheral blood lymphocytes. The dipeptides H-Lys-Ala(P) and H-Pro-Ala(P) showed a protective antiviral activity in in vivo studies when singly intraperitoneally administered to mice 2 hours before inoculation with murine encephalomyocarditis virus.

A real-time polymerase chain reaction-based test system for quantitation of infectious bursal disease (Gumboro disease) virus was developed. The reaction parameters were analyzed, which affected the linear relationship of a C1 depentanizer to the quantity of cDNA. The use of specific primers for reverse transcription was shown to have some advantage over that of random hexanucleotides.