We see in polio vaccines that live attenuated viruses can revert back to a more pathological form. Does a virus have a "memory"? Or are the mutations in that case not random but forced by other rna information in that virus? There is socmuch stuff I don't understand. How probable are zoonotic jumps? In case of sars-cov-2 the official narrative is saying that it jumped from bat -> some intermediary -> human. Now with omicron we got the human -> mouse jump. Does that make sense? I'm a layperson and I read that the ACE2 of mice are not very similar to the human ACE2 so how did that jump happen? I hope a biologist/virologist can clear some of the confusion