The Division of Laboratory Diagnostic Analysis of the Capital Regional Center for Disease Control and Prevention conducted variant analysis on SARS-CoV-2-positive samples from the National Incheon Airport Quarantine Station, National Incheon Quarantine Station, and private diagnostic testing centers at Incheon International Airport from February 15, 2021, to March 2023. In total, 13,098 samples from COVID-19 cases from 130 countries were analyzed using the Genomic Surveillance project in the Republic of Korea. They included 12,364 cases (94.4%) of the Omicron family; 658 cases of Delta (5.0%); 55 cases of Alpha (0.4%); 5 cases of Beta; 4 cases of Epsilon; 3 cases each of Gamma, Kappa, and Iota; 2 cases of Eta; and 1 case of Theta SARS-CoV-2 variants. The countries with the highest number of imported cases were Indonesia in 2021 (222 cases, 28.0%), the United States in 2022 (1,942 cases, 17.1%), and China from January to March 2023 (345 cases, 37.3%).Most variants of concern in the Republic of Korea were introduced from various countries. As the importation of recombinant variants generated among sublineages of the Omicron variant increases in 2023, there is an increasing need for genomic analysis through whole-genome sequencing of SARS-CoV-2 variants to enable more accurate classification. Capital Regional Center for Disease Control and Prevention plans to continue to conduct SARS-CoV-2 variant analysis based on a 24-hour diagnostic testing system to effectively monitor the imported cases infectious diseases from abroad and take efficient domestic quarantine measures.
