NCIPD has successfully analyzed 87 clinical samples with SARS-CoV-2 by next-generation whole genome sequencing. The samples were collected from patients with COVID-19 between 09.12.2022-11.01.2023 and were sent from 14 different medical institutions in 10 districts of the country.

The Omicron variant was detected in all clinical samples and the proportion was as follows: BA.2.3.20 (1.1%), BA.5.x (16.1%), BE.x/BF.x (37.9%), BN.x (11.5%), BQ.1.x (26.4%), CL.1/CP.1 (2.3%), XBB.1.5 (1.1%), other XBB.х (3.4%).

For the first time in Bulgaria, variant XBB.1.5 was identified. WHO is monitoring XBB.1.5 with caution due to its potential for accelerated spread and reduced neutralization by vaccine and natural immunity from previous 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.