National Center of Infectious and Parasitic Diseases, Sofia, Bulgaria

Announcement of the spread of SARS-CoV-2 variants in the country 14 March 2022

The National Center for Infectious and Parasitic Diseases (NCIPD) reports that 355 clinical samples with SARS-CoV-2 collected from 01 February – 23 February 2022 were analyzed by next-generation whole-genome sequencing. The clinical samples were collected in 34 different medical centers, from 20 districts of the country.

344 (96,9%) of the samples were defined as Omicron, 244 of which subvariant (ВА.1 or ВА.1.1) and 100 (BA.2). 11 (3,1%) of the samples were defined as Delta (B.1.617.2) or Delta subvariants (AY.*). Nextclade v1.13.2 and Pangolin COVID-19 Lineage Assigner v3.1.20 programs were 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.