52 cases of the Omicron coronavirus variant were registered in Bulgaria after a single-cell whole-genome sequencing performed by the National Center for Infectious and Parasitic Diseases. 

The samples were taken until January 3, 2022 in 13 hospitals located in 9 Bulgarian districts. 38 cases of the Omicron variant were reported in Sofia-city. Cases of the Omicron variant were also reported in the following districts- Pazardzhik, Sofia-district, Burgas, Varna, Plovdiv, Ruse, Sliven and Stara Zagora.

The Omicron variant accounts for 10.3% of all 505 positive clinical samples. The Delta variant and its subvariants account for 89.7% of the positive samples.