Coronavirus disease 2019, abbreviated to COVID-19, is a shorter name given to a novel virus identified as Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2). It is an infectious disease caused by then new coronavirus that started to develop from Wuhan, China, in late 2019. It causes a sudden respiratory infection, which can be mild especially among children and healthy adults, but can be fatal to old people as well as those with underlying medical condition. Some 20-30% of infected people have required hospitalization, about 4% being seriously ill and for some of them the disease being fatal. As it is a new virus, nobody has prior immunity, which means that the entire human population is potentially susceptible to COVID-19 infection. (ECDC, 2020.)