copyright 2013-2020
yongkee.hong

coronaviruses are a group of viruses that cause diseases in mammals and birds. in humans, the virus causes respiratory infections which are typically mild but, in rare cases, can be lethal. in cows and pigs they may cause diarrhea, while in chickens it can cause an upper respiratory disease. there are no vaccines or antiviral drugs that are approved for prevention or treatment. wikipedia