Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has spread rapidly worldwide (Lai et al., 2020). As of June 20, 2021, SARS-CoV-2 had affected more than 179 060 045 people globally, causing over 3.87 million deaths. In the USA, as many as 34 401 766 individuals had tested positive for COVID-19, and the death toll had reached 617 091 people (Baidu, 2021). The symptoms of COVID-19 include a dry cough, fever, diarrhea, fatigue, pneumonia, and conjunctivitis.
