What is Herd Immunity? Herd Immunity? What is this term again? The corona virus is indeed a unique virus that has not been solved exactly how to disable it, and because of that virus, we are familiar with new terms. ODP, PDP, Social Distancing, and finally, the latest, herd immunity. It is indeed a h****le if fighting against invisible enemies. Everything relies on research and treatment options that still reek of possibilities.