Interesting point. Would most Amish agree to take a Covid test or visit a modern doctor if they were sick though?

My impression was they prefer to rely on prayer and home remedies over modern medicine. If so, its unlikely all their cases got reported.

I'm a bit skeptical, but maybe there's something to it. The Amish are a rather insular community. I wouldn't be surprised if they had differences in immune system from the average American because of their tendency to marry inside their community, keep livestock, and rely less on modern healthcare.

Studies have shown there are immune system related drawbacks to living in a largely sterile environment without frequent exposure to animals. Higher risk of allergies for example. There are other coronaviruses which pre-date Covid too. Maybe that lifestyle is just more likely to lead to similar exposures and natural immunity.