Text #9428"Andronovo culture", in .
At Kytmanovo in Russia between Mongolia and Kazakhstan, dated 1746–1626 BCE, a strain of yersinia pestis was extracted from a dead woman’s tooth in a grave common to her and to two children. This strain’s genes express flagellin, which triggers the human immune response. However by contrast with other prehistoric yersinia pestis bacteria, the strain does so weakly; later, historic plague does not express flagellin at all, accounting for its virulence. The Kytmanovo strain was therefore under selection toward becoming a plague (although it was not the plague). The three people in that grave all died at the same time, and the researcher believes that this para-plague is what killed them.
Simon Rasmussen et al. (2015). “Early Divergent Strains of Yersinia pestis in Eurasia 5,000 Years Ago”. Cell 163: 571–582. doi:10.1016/j.cell.2015.10.009., S14-15. This sample is marked “RISE505”.