COVID-19, also known as the coronavirus disease, is a highly contagious illness caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The virus was first identified in Wuhan, China in December 2019 and has since spread globally, causing a worldwide pandemic. The virus is primarily spread through respiratory droplets that are expelled when an infected person talks, coughs, or sneezes. It can also be spread by touching a surface or object that has the virus on it and then touching mouth, nose, or eyes. To prevent the spread of COVID-19, public health authorities have recommended a number of measures, such as wearing masks, physical distancing, hand hygiene, testing, and contact tracing. Vaccination is also recommended as an important measure to control the pandemic. In the period after COVID-19, it is recommended to keep wearing mask especially in the crowded area.