Methodology for Estimating the Basic Reproductive Number of Current Variants of the Virus SARS-CoV-2

Abstract

Relevance. The high infectivity and mutagenicity of SARS-CoV-2, combined with the relative short duration of the immune response, means that the problem of controlling the incidence of COVID-19 will continue to be relevant. Aims. To plan anti-epidemic measures, you need to know the quantitative value of the basic reproductive number (R0), however, the available methods for estimating the R0 made it possible to estimate it only for the initial version of SARS-CoV-2. In this regard, the task was set to develop a method for estimating R0 for current pathogen variants based on the rate of change from one variant to another, including both viruses and bacteria. Materials and methods. A modification of the SIR model for two variants of SARS-CoV-2 and actual data on the incidence of COVID-19 and the results of sequencing the virus SARS-CoV-2 isolated in Moscow are used. Results. It was found that for the SARS-CoV-2 Delta variant R0 was about 10, and for the current Omicron variants it exceeds 30. Discussion. In contrast to existing methods, the proposed method allows one to estimate R0 in the context of anti-epidemic measures, as well as by the dynamics of morbidity in a population with a collective immune status, taking into account the typical structure of the circulating SARS-CoV-2. Conclusion. The proposed method makes it possible to estimate the change in the basic reproductive number of the SARS-CoV-2 based on the rate of displacement of one variant by another