I am not an expert in communicable diseases or genetics, so maybe I am wrong about this, but another issue that I haven't seen brought up much is that anti-vaccination groups endanger not just the small number of people who rely on herd immunity due to medical issues that prevent them from getting vaccinations, but also those of us who already have vaccinations. If nearly eradicated diseases spread through groups of unvaccinated people, it provides more opportunities for the disease to mutate into a form from which our current vaccinations do not protect.
Should a person who happens to be immune to the effects of Ebola yet is still contagious be allowed to walk around New York as they please because it is their right not to get it treated?