National Center of Infectious and Parasitic Diseases, Sofia, Bulgaria

Communication on the spread of SARS-CoV-2 variants in the country January 15, 2025

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 in 9 regions of the country between 03.10 and 28.11.2024 and sent by 12 laboratories.

Omicron and its subvariants were detected in all samples. ХЕC 16 (17%) of the proven SARS-CoV-2 variants were defined by WHO as Variants Under Monitoring (VUM) (as of 20 December 2024). KP(FLiRT) subvariants were also detected 39 (41.5%), in addition to the detected subvariants: JN.x (1/1.1%), LB.x (4/4.3%), MC.x (15/15.9%) and (19/20.2%) other subvariants of SARS-CoV-2 were detected.

Nextclade v3.8.2 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 which are of increased public health importance.