Genetic Mutation of SARS-CoV-2 during Consecutive Passages in Permissive Cells

Dear Editor,The ongoing COVID-19 disease, caused by severe acute respiratory syndrome coronavirus 2 （SARS-Co V-2）, has led to over 112 million confirmed cases and 2.4 million deaths in more than 220 countries as of 25 February 2021（WHO 2021）. Hospital-admitted patients show clinical features including fever, dry cough, fatigue, dyspnea,lymphopenia, and pneumonia with radiological groundglass lung opacities （Huang et al. 2020; Guan et al. 2020）.SARS-Co V-2 was quickly isolated and could be detected in clinical samples, such as nasopharyngeal swabs, sputum,alveolar lavage fluid, and feces, as well as occasionally in seminal fluid and tears among other sources （Bhat et al.2020; Li et al. 2020）, which means that it can infect a variety of human tissues and organs.