To detect and differentiate current influenza B viruses of both evolutionary lineages, the sensitivity of a new variant of microcultural enzyme immunoassay (cell-ELISA) has been assessed using a panel of 16 monoclonal antibodies (mAbs) specific to hemagglutinin of influenza B viruses. Nasopharyngeal samples from patients with acute respiratory viral infections (ARVI) were analyzed. The cell-ELISA was tested for the detection of influenza B viruses in 192 PCR-positive clinical samples. The highest sensitivity in detection and differentiation of influenza B viruses of the Yamagata and Victoria evolutionary lineages was shown for 5B11 and 5B7 mAbs, respectively. The detection of Yamagata influenza B viruses with cell-ELISA in PCR-positive clinical samples obtained in 2018 showed a lower sensitivity (61.7

Antiepidemic measures were limited effectiveness for several years Objectives of this research were formulated as an assessment of the immunogenicity activity of the influenza virus A(H1N1)pdm09 in the composition of modern trivaccines Immunogenicity of the influenza virus A(H1N1)pdm09 in the vaccinated by vaccine was assessed by graphing, reflecting the dynamics of the multiplicity growth of antibodies (MG) and medium ratio of antibodies increasing (MR) in sera for several groups vaccinated. For comparison of vaccinated immunity was determined by traditional methods of evaluation of the immune response. As a result of the research, differences in the immunogenicity activity of the virus were revealed, which are reflected in antibody titers and the multiplicities of their growth from 2 to 4 - 8 times with the applying of similar quality vaccines. These changes couldn’t be observed with accounting study of the immune response. When immunized with a vaccine with an antigen dose of 5 mg HA identified a group of«silent» volunteers (8%) who did not respond to promotion with antigen A(H1N1)pdm09. Increasing dose of the influenza virus A(H1N1)pdm09 to 15 mg/dose in the split vaccine were result of the elimination of the group of«silent» volunteers. Simultaneously was observed a significant increase in the immune response in serum titers (up to 32-fold) and antibody growth rates Accordingly, using of the graphical form of accounting made it possible to better assess the details of the formation of collective immunity to the virus A(H1N1)pdm09 and the nature of its deviations in a number of cases.

The article discusses the results of study that demonstrated the possibility of successful application of radial hemolysis reaction in analyzing the human inoculation immunity to new strains of influenza virus serotype A A (H5N1) andA (H5N2). The radial hemolysis reaction provides accurate results on introduction of erythrocytes of horse or sheep into hemolytic system instead of erythrocytes of hens applied previously. The technique combines high sensitivity (in comparison with reactions of hemagglutination-inhibition and micro-neutralization, correlation coefficient 0.84-0.85) and total absence of inhibitors impact on the reaction results. During the investigation of immune response of patients who had pandemic virus A (H1N1) pdm09, radial hemolysis reaction demonstrated not only primary detection of antibodies to virus-agent (67°%) during pandemic, but also elective heightened sensibility in the zone of low titer serums (1:20) in hemagglutination-inhibition reaction. These characteristics are very important in analysis of antibodies levels at early stages of disease. The radial hemolysis reaction continues to be a reliable instrument in evaluating qualitative and quantitative indicators of humoral immunity in ill patients and persons inoculated with new strains of human influenza virus.

The article discusses the results of study that demonstrated the possibility of successful application of radial hemolysis reaction in analyzing the human inoculation immunity to new strains of influenza virus serotype A - A (H5N1) and A (H5N2). The radial hemolysis reaction provides accurate results on introduction of erythrocytes of horse or sheep into hemolytic system instead of erythrocytes of hens applied previously. The technique combines high sensitivity (in comparison with reactions of hemagglutination-inhibition and micro-neutralization, correlation coefficient 0.84-0.85) and total absence of inhibitors impact on the reaction results. During the investigation of immune response of patients who had pandemic virus A (H1N1) pdm09, radial hemolysis reaction demonstrated not only primary detection of antibodies to virus-agent (67%) during pandemic, but also elective heightened sensibility in the zone of low titer serums (1:20) in hemagglutination-inhibition reaction. These characteristics are very important in analysis of antibodies levels at early stages of disease. The radial hemolysis reaction continues to be a reliable instrument in evaluating qualitative and quantitative indicators of humoral immunity in ill patients and persons inoculated with new strains of human influenza virus.

An indirect enzyme immunoassay (EIA) using the purified fraction of surface viral glycoproteins (GP) as an antigen for solid phase sensitization was not shown to be a specific method for the differential detection of influenza A(HS) (HS-Ab) virus antibodies (Abs) due to total conservative epitopes in the structure of GPs of influenza A(H5) and A(H1NI) viruses. The cross activity of some monoclonal Abs (MAbs) to influenza A(H5) and A(HIN1) viruses, which had been obtained at the Research Institute of Influenza, was proof of the presence of total immunodominant determinants in the structure of influenza H1 and H5 virus hemagglutinin (HA). In this connection, an EIA, which was based on the competition of influenza A(H5) H5-Ab virus HA-specific MAbs in the test sera for an association with influenza A(H5) virus, was proposed for the subtype-specific detection of H5 Ab. Comparison of the results of competitive EIA (cEIA), microneutralization (MN) test and HA inhibition test (HAIT) (using equine red blood cells) in the examination of sera obtained from 44 volunteers immunized with inactivated vaccine containing influenza A/Indonesia/5/2005 (H5N1) virus showed the high sensitivity and specificity of cEIA in detecting H5-specific Abs. The effectiveness of cEIA for the sera strictly positive for the content of H5 Abs was close to that of MN test and was 9-34% higher than HAIT (depending on those used in the analysis of H5 virus antigens). cEIA may be proposed to assess new influenza vaccines as an additional laboratory test. Since the infectious virus is not used during cEIA, it may be recommended for the serodiagnosis of influenza A(H5) at practical virological laboratories.