This would be lucky. Plus, I read on NYT, from a Harvard researcher, that the vax should provide some protection. Especially if you’ve had the booster, as it broadens the immune response.
It was speculated that Omicron could of mutated in a person with HIV who had limited immunity. That it would of had time in their system to reproduce and mutate. Vax rates in S Africa are pretty low (27%) and they have a high prevalence of HIV. Just found it interesting.