Properties of influenza viruses that caused epidemic increases in morbidity in Russia and countries of the world during 2022–2023. The effectiveness of vaccine prophylaxis

Abstract

The purpose of this work was to determine the characteristics of the circulation of various viral respiratory pathogens during the epidemic season 2022–2023 against the background of the ongoing evolutionary variability of SARS-CoV-2.
 Materials and methods. The article uses methods used in «traditional» and «hospital» epidemiological surveillance of acute respiratory viral infections.
 Results and discussion. The period from October 2022 to September 2023 was characterized by early and high activity of influenza A(H1N1)pdm09 virus, which was replaced by influenza B virus. The antigenic and genetic properties of strains were closely related to influenza vaccines viruses recommended by WHO experts for the current season. The effectiveness of influenza vaccines was confirmed (75.0%). All of the studied influenza A(H1N1)pdm09, A(H3N2) and B epidemic strais retained sensitivity to drugs with antineuraminidase activity. The structure and share of other ARVI pathogens have changed somewhat compared to the previous season: There was a tendency to increase the activity of HAdV and HMPV; almost equivalent activity of HRsV, HRV, HCoV and HBoV; and a decrease in HPIV activity. At the same time, the frequency of other ARVI pathogens did not reach the indicators of the pre-pandemic COVID-19 period. The rationale for updating the composition of influenza vaccines for the countries of the Northern Hemisphere in the 2023–2024 season is given.