There is a study that claims that genes associated with autoimmune diseases increased survival during the black death epidemic by 40% and frequency of these genes increased a lot in the 14th century Europe [1]. I haven't yet seen independent confirmations but I can imagine that paranoid immune system can be beneficial depending on circumstances. If we eradicate autoimmune diseases then there's a chance we won't survive the next big pandemic.
> If we eradicate autoimmune diseases then there's a chance we won't survive the next big pandemic.
IMO it seems more likely that we'd find effective treatment which mitigates symptoms of autoimmune disease than a treatment that irreversibly eradicates the disease (including from subsequent generations, even?).
[1] https://www.nih.gov/news-events/nih-research-matters/how-bla...