National Center of Infectious and Parasitic Diseases, Sofia, Bulgaria

Announcement of the spread of SARS-CoV-2 variants in the country 25 March 2022

The National Center for Infectious and Parasitic Diseases (NCIPD) reports that 457 clinical samples with SARS-CoV-2 collected from 08 February – 10 March 2022 were analyzed by next-generation whole-genome sequencing. The clinical samples were collected in 36 different medical centers, from 24 districts of the country.

456 of the samples were defined as Omicron, 243 (53,3%) of which were subvariant ВА.1 or ВА.1.1 and 213 (46,7%) BA.2. One of the samples was defined as Delta B.1.617.2. Pangolin COVID-19 Lineage Assigner v3.1.20 program was used to define SARS-CoV-2 variants. An epidemiological analysis is being carried out.

For information on the classification of SARS-CoV-2 variants and sub-variants, please visit: https://cov-lineages.org/index.html

For an up-to-date classification of the variants of concern (VOC), please visit:

https://www.ecdc.europa.eu/en/covid-19/variants-concern

https://www.who.int/en/activities/tracking-SARS-CoV-2-variants/

The NCIPD continues to monitor the spread of SARS-CoV-2 in the country, with a focus on VOC, altered virulence and immunogenicity that are of increased public health importance.