Variation that protected against Black Death helps against respiratory diseases, but increases autoimmune disease risks

The same genetics that helped some of our ancestors fight the plague is still likely to be at work in our bodies today, potentially providing some of the population with extra protection against respiratory diseases such as COVID-19, according to research led by scientists at University of Bristol. However, there is a trade-off, where this same variation is also linked to increased autoimmune diseases such as rheumatoid arthritis and inflammatory bowel disease.