Sequence variation among SARS-CoV-2 isolates in Taiwan

Taiwan experienced two waves of imported cases of coronavirus disease 2019 (COVID-19), first from China in January to late February, followed by those from other countries starting in early March. Additionally, several cases could not be traced to any imported cases and were suspected as sporadic local transmission. Twelve full viral genomes were determined in this study by Illumina sequencing either from virus isolates or directly from specimens, among which 5 originated from clustered infections. Phylogenetic tree analysis revealed that these sequences were in different clades, indicating that no major strain has been circulating in Taiwan. A deletion in open reading frame 8 was found in one isolate. Only a 4-nucleotide difference was observed among the 5 genomes from clustered infections.