Features of the COVID-19 Epidemic Process in Each of the of the Five Waves of Morbidity in Russia

Abstract

Aim. To assess the intensity of the epidemic process in each of the five waves of COVID-19 in Russia.Materials and methods. The data on morbidity, hospitalization and deaths from COVID-19 of the population as a whole and by age groups from 48 (in the I rise) to 54 cities (in the V wave) and data from the website of the Russian consortium for sequencing coronavirus genomes were analyzed.Results. The nature of the course of the first 5 waves in the incidence of COVID-19 in Russia remains undulating. The waves in morbidity began in megacities, and the direction of spread across the FD differed in different waves of morbidity. The results of gene sequencing showed the participation of the main genovariants of the coronavirus in the etiology of diseases up to 3-4 waves. Some genovariants identified earlier received maximum distribution in the following wave. In Russia, the European descendants of the Wuhan strain (74.4%) were dominant in the I wave in morbidity, in the II wave – its daughter genovariants (68.5%), in the III – AY.122 (80.1%), in the IV – AY.122 (84.7%) and in the V wave – Omicron (76.7%).Conclusions. The features of each wave in the incidence of COVID-19 depended on the properties of the dominant genovariants: their ability to transmit from person to person and virulence. The rate of spread of the epidemic by FD, the susceptibility of all age groups and the intensity of epidemics were maximal during the period of the V wave in morbidity with the Omicron gene variant. Mortality was minimal in the I wave of morbidity, maximal in the IV with AY.122 strains and low in the V wave with Omicron genovariants. The influence of the season of the year was manifested in the summer season by an increase in the incidence of COVID-19 earlier in the Russian Federation as a whole (immediately after megacities) than in most federal districts, but with a lower incidence.