Before revision: After the first infected patient detected in Wuhan, China in December, 2019 with the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus, the COVID-19 (CO means corona, VI is virus, D is disease, 19 is the year of discovery) disease spread globally due to its high contagious nature and became an ongoing pandemic. Also, the lack of vaccines and efficacious drugs to treat infected patients is a great problem to cope this pandemic.
After revision: After the first infected patient detected in Wuhan, China in December, 2019 with the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus, the COVID-19 is the main concern of this pandemic.