Some historical perspective:

White Christians in Europe during the "Dark Ages" notoriously lacked hygiene. Like the COVID Pandemic today, that was one of the reasons the Bubonic Plague spread so widely. By contrast, Jews and Muslims exercised hygiene as part of their religious practices. As a result, they caught that deadly disease at a significantly lower rate. And as a result of that, Christian Europeans "connected the dots" (the same way MAGA anti-vaxxers do today) to conclude that the Jews and Muslims must be responsible for the Plague itself.

Both physical diseases (like COVID) and moral diseases (like racism) are spread by ignorance.