Abstract
We conducted a genomic surveillance of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) by performing full-length genome analysis of the virus, targeted gene sequencing, and real-time reverse transcription polymerase chain reaction in Daegu Metropolitan City and Gyeongsangbuk-do between February 2021 and August 2023. Samples of patients with coronavirus disease 2019 were collected from institutes of health and environment, private diagnostic referral laboratories, and medical institutes. Among 20,159 patient samples collected, there were 15,402 cases of the Omicron (76.40%), 3,922 cases of Delta (19.46%), 195 cases of Alpha (0.97%), 176 cases of Epsilon (0.87%), 3 cases of Beta, 3 cases of Iota, and 1 case of Kappa SARS-CoV-2 variants. Prevalence of the variants varied by year, five variants (Alpha, Beta, Delta, Omicron, and Epsilon) were mostly prevalent in 2021. Delta and Omicron family were prevalent in 2022, and only the Omicron variant was prevalent in 2023. The prevalent Omicron sub-variants (n=2,756) included BA.1 (n=32, 1.16%), BA.2 sublineage (n=960, 34.83%), BA.4 (n=11, 0.40%), BA.5 (n=1,004, 36.43%), and XBB recombinants (n=719, 26.09%). Among XBB recombinants, the prevalent subvariants included XBB.1.9.1 (n=180, 6.53%), XBB.1.5 (n=140, 5.08%), XBB.1.16 (n=99, 3.59%), XBB.1.9.2 (n=88, 3.19%), and EG.5 (n=88, 3.19%). These results suggested that continuous genomic surveillance is important to monitor the SARS-CoV-2 variants emergent in the Daegu Metropolitan City and Gyeongsangbuk-do.