National Center of Infectious and Parasitic Diseases, Sofia, Bulgaria

Communication on the spread of SARS-CoV-2 variants in the country October 06, 2023

The NCIPD has successfully analyzed 94 clinical samples with SARS-CoV-2 by next-generation whole genome sequencing. The samples were collected from patients with COVID-19 from 6 regions of the country in the period 03.07-27.09.2023 and were sent by 9 laboratories.

Omicron and its subvariants were detected in all samples, including three subvariants defined by WHO as circulating variants of interest (VOIs): EG.5.1 in 3 (3.2%), XBB.1.16 in 3 (3.2%) and XBB .1.5 in 2 (2.1%). In addition, EG.x 28 (29.8%), ХBB.x 38 (40.4%) and 28 (29.8%) other subvariants were identified.

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.