Circulating Variants of SARS-CoV-2 Among Macedonian COVID - 19 Patients in the First Year of Pandemic.

Genomic epidemiology has proven to be a useful tool for investigating pandemic outbreaks and tracking pathogen spread and evolution. This study describes the circulation of SARS-CoV-2 strains in N. Macedonia during a period of one year, encompassing three waves of the COVID-19 pandemic. A certain percentage (2-3%) of positive cases were continuously selected and analyzed by whole genome sequencing (WGS) technology. Using this approach, a total of 337 SARS-CoV-2 genomes were sequenced and 26 different lineages belonging to 7 clades were detected. During the first wave of the pandemic, the most dominant lineage was B.1.1, followed by B.1.1.70, which became the most dominant in the second wave. The B.1.1.7 lineage completely overpassed all other variants in the third wave. Our study strengthens the notion that the progression of COVID-19 pandemic is associated with emergence of new SARS-CoV-2 variants with increased virulence. The measure of the impact of this viral dynamic on the spread of the pandemic should be evaluated in association with other factors that might influence the transmission.