With all the attention on the pandemic, it’s amazing how little people still know about the novel coronavirus. COVID-19 is the disease caused by one of seven types of known human coronaviruses. Like the MERS and SARS coronaviruses, it may have evolved from a virus previously found in animals, though that theory has come under increased scrutiny of late. These other known coronaviruses cause a significant percentage of colds in adults and children, and aren’t a serious threat for otherwise healthy adults.
All viruses accumulate mutations over time, and the virus which causes COVID-19 is no different. Therefore mutations, now changed, are harder to identify and control.