In December 2000, Researchers from the National Cancer Institute in Maryland, USA, analysed DNA samples from 100 residents in Eyam, selected on the basis that the family should be traceable back to the seventeenth century when the village was struck by bubonic plague.

They found that a higher than normal proportion of the villagers carried a genetic mutation referred to as "CCR5-Delta 32" or just "Delta 32", which gives immunity to bubonic plague. The story was told in an excellent Channel Four documentary, "Riddle of the Plague Survivors", in February 2002.

In Eyam, where almost everyone was exposed to plague, those not carrying the mutation would die, while those with the mutation survived to produce children, who would also carry Delta 32. Sure enough, even after more than 300 years, the population still shows an unusually high incidence of the mutation.

The research sparked enormous interest, not least because it is known that the Delta 32 mutation, if inherited from both parents, gives immunity to HIV / AIDS.

We soon found that many people were asking about Delta 32, and produced a temporary display giving more details. This has now been incorporated into the main display, with even more information.