Population immunity for influenza in population of Sverdlovsk Region in epidemic season of 2018–2019

Abstract

Donor blood serum was tested to detect antibodies against circulating influenza viruses. The titer of specific antibodies was determined in the hemagglutination inhibition test (RTGA) against influenza viruses A/California/07/09(H1N1) pdm09, A/HongKong/4801/14(H3N2) and B/Brisben/46/15. In the pre-epidemic period 2018–2019, the immune layer of people with conditionally protective titers of antiviral antibodies was detected in terms of the lowest to A(H3N2) virus (50.0 %), the highest to influenza B (85.4 %). In the post-epidemic season of 2018–2019, the immune layer to influenza A(H1N1) pdm09 virus did not change significantly, which could indicate the preservation of the activity of this virus in the adult population; an increase in the immune layer of individuals with protective titers of antibodies to influenza A(H3N2) – 67.4 % and a decrease in influenza B virus – 49.2 %. A comparison of the results of laboratory data carried out in the pre- and post-epidemic seasons revealed significant differences in the number of people with average antibody titers against influenza A(H3N2) and B viruses (p < 0.05).