Last night Doctor was on Jesse Waters show,claimed Omicron escaped during experiment on mice in South Africa.
“Murine coronavirus is an important pathogen in the laboratory mouse and the laboratory rat. It is the most studied coronavirus in animals other than humans, and has been used as an animal disease model for many virological and clinical studies.”
https://en.wikipedia.org/wiki/Murine_coronavirus
Perhaps rodent lab workers should be studied to determine if they have better Covid immunity.