[Formation of antibodies against neuraminidase of A/California/07/2009 (H1N1) influenza virus after immunization with live monovalent influenza vaccine].

Aim: Detection of antibodies against neuraminidase (NA) of A/California/07/2009 (H1N1) influenza virus in blood sera of volunteers after the immunization with live monovalent influenza vaccine (LIV).
Materials and Methods: Neuraminidase enzyme activity inhibition by antibodies test with reassortant strain A(H7N1) containing NA of pandemic strain was used. Anti-neuraminidase IgG antibodies against whole reassortant virus A(H7N1) and purified NA of A/California/07/2009 (H1N1) strains were determined by enzyme immunoassay (EIA).
Results: After two immunizations with LIV of seronegative individuals a 1.5 times mean increase of antibodies against homologous neuraminidase was detected (by hemagglutinin inhibition reaction). The high level of anti-neuraminidase antibodies were detected in individuals that had been naturally infected. A correlation between anti-neuraminidase IgG antibody titers obtained in EIA with whole reassortant virus A(H7N1) and purified protein was demonstrated.
Conclusion: Modified sialidase activity inhibition method and EIA with reassortant diagnostic strain can be applied to evaluate anti-neuraminidase antibodies.