[Formation and protective functions of antibodies to neuraminidase of the influenza A virus]

The features of production and protective properties of antineuraminidase antibodies in subjects of various ages with influenza infection caused by currently important influenza A virus strains of H1N1 and H3N2 serosubtypes were studied. In children, antineuraminidase antibodies were found to accumulate less intensively than in adults and in infants under 1 year they were detected extremely rarely. In young infants, their titres after the disease decreased more rapidly than antihemagglutinin titres. As compared with adults, in younger children these antibodies have a higher protective role in modifying the severity of influenza infection. A direct correlation between the age of the children and the levels of antineuraminidase antibodies demonstrable in them was established. Within the same period of time, ratio of antihemagglutinins and antineuraminidase antibodies was shown to differ significantly in the population of different regions of the country. The results of trials in volunteers of 10 strains as candidates for a live influenza type A vaccine (H3N2) indicate considerable variability of the immunogenic potency of hemagglutinin and neuraminidase of these strains.