SARS-CoV-2 Variants Monitoring Using Real-Time PCR

Abstract

According to the temporary recommendations of the 2021 World Health Organization (WHO), in addition to whole-genome sequencing, laboratories in various countries can also screen for known mutations utilizing targeted RT-PCR-based mutation detection assays. The aim of this work was to generate a laboratory technique to differentiate the main circulating SARS-CoV-2 variants in 2021–2022, when a sharp increase in morbidity was observed with the appearance of the Omicron variant. Real-time PCR methodology is available for use in the majority of scientific and diagnostic institutions in Russia, which makes it possible to increase the coverage of monitoring of variants in the territories of all 85 regions in order to accumulate information for the Central Services and make epidemiological decisions. With the methodology developed by the Central Research Institute of Epidemiology of the Federal Service for Surveillance on Consumer Rights Protection and Human Wellbeing (FSSCRP Human Wellbeing) (CRIE), more than 6000 biological samples have been typed, and 7% of samples with the Delta variant and 92% of samples with the Omicron variant have been identified as of 25 August 2022. Reagents for 140,000 definitions have been supplied to regional organizations.

Keywords

• SARS-CoV-2 variants
• tracking variants
• surveillance
• real-time PCR
• Delta
• Omicron