Chance of mutation depends mostly on the number of infected —- applying antibiotics is problematic because it is a repeated process, and the net amount of cell divisions is huge with iterating killing and “letting go”. With effective and strict measures, the pandemic could quickly die out with basically minimal chance of a super-mutation.

The current some half of the world somewhat protected, while other parts are breeding grounds is a pretty bad state to be at, with a potential mutation turning up and endangering the protected people as well again.