National Center of Infectious and Parasitic Diseases, Sofia, Bulgaria
Communication on the spread of SARS-CoV-2 variants in the country October 24, 2023

The NCIPD has successfully analyzed 88 clinical samples with SARS-CoV-2 by next-generation whole genome sequencing. The samples were collected from patients with COVID-19 from 14 regions of the country in the period 14.09-12.10.2023 and were sent by 9 laboratories.

Omicron and its subvariants were detected in all samples, in one of the identified patients, BA.2.86 or "Pirola (1.1%)", designated by WHO as variants under monitoring (VUMs), was demonstrated. Subvariants designated by WHO as variants of interest (VOIs) were also detected: EG.5 in 1 (1, 1%), EG.5.1 in 2 (2.3%), XBB.1.9.2 in 1 (1, 1%), and XBB.1.5 in 1 (1.1%). 11 (12.5%), XBB.x 31 (35.2%) and 46 (52.3%) other subvariants.

Pangolin COVID-19 Lineage Assigner v4.3. 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.