National Center of Infectious and Parasitic Diseases, Sofia, Bulgaria

Communication on the spread of SARS-CoV-2 variants in the country November 8, 2024

The NCIPD has successfully analyzed 96 clinical samples with SARS-CoV-2 by next-generation whole genome sequencing. The samples were collected from patients with COVID-19 from 10 regions of the country in the period 06.08-30.09.2024, and were sent by 11 laboratories.

Omicron and its subvariants were detected in all samples. 44 of the proven SARS-CoV-2 variants were defined by WHO as Variants Under Monitoring (VUM) (as of 24 September 2024): KP.3.1.1/FLiRT (41/42.7%), KP.3/FLiRT (1/1%), and ХЕC (2/2%). Other KP3(FLiRT) subvariants were also shown in 16/16.7%. In addition, subvariants were demonstrated: JN.x (3/3.1%), LB.x (4/4.2%), MC.x ( 13/13.6%) and 16/ 16.7% 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.