There are four endemic coronaviruses that infect humans. One of them uses the same receptor ACE2 to infect cells. That one is getting a harder look. There is a

There are four endemic coronaviruses that infect humans. One of them uses the same receptor ACE2 to infect cells. That one is getting a harder look. There is also SARS which is extinct. And MERS which is producing sporadic outbreaks.