Who had survived in the black plague?

The Black Plague claimed the lives of around two hundred million people, which represented roughly a third of the European population at the time.

Some survivors of the Black Plague had a genetic mutation which made them less susceptible to catching the disease. For example, individuals without a protein named CCR5 could not be infected by HIV which would go on to cause millions of deaths and is still not eradicated or widely spread globally in certain places such as Southern African Countries. There may have been a similar correlation due to some unknown reasons or due to natural selection during the black plague period as well; we lack direct evidence for it since DNA information on deceased is hard to gather but it isn't unlikely or illogical.