Local tales in the small, central-England village of Eyam tell befuddling stories of plague survivors who had close contact with the bacterium but never caught the disease. Dr. O'Brien's
...work with HIV and the mutated form of the gene CCR5, called "delta 32," led him to Eyam. In 1996, research showed that delta 32 prevents HIV from entering human cells and infecting the body. O'Brien thought this principle could be applied to the plague bacteria, which affects the body in a similar manner. To determine whether the Eyam plague survivors may have carried delta 32, O'Brien tested the DNA of their modern-day descendents. What he found out was startling ...Read the whole thing.