Some people are the descendants of people who survived great…

Sоme peоple аre the descendаnts оf people who survived greаt epidemics of Bubonic Plague (or smallpox) centuries earlier. It is believed these ancestors who survived these epidemics had a mutation in their cells and consequently carried a mutant receptor to which the Plague pathogen (or smallpox pathogen) could not bind. This mutation was passed down through generation, making descendants of these survivors now also resistant to _________