Nu skapar man covid19-möss i labb för att kunna forska på viruset. Normalt sett får inte möss Corona.

"In humans, the virus´spike protein attaches to the ACE2 receptor on epithelial cells and enters the lungs.  But coronaviruses like SARS-CoV and SARS-CoV-2 don’t infect your normal laboratory mouse — or, if they do, it’s at a very low rate of infection and the virus doesn’t replicate readily.
That’s because the virus’ spike protein doesn’t recognize the regular lab mouse’s ACE2 receptor.
So the mice are relatively protected."

https://www.smithsonianmag.com/science-nature/mouse-squad-covid-19-180974927/