[SAJ]

Interesting notion. Won't work. ''Black Plague'' is a bacterial disease, specifically the work of Yersinia pestis. No observable correlation between successive generations' increased resistance to successive bacterial pandemics and any viral pandemic.

The classic example here is the so-called ''Spanish Influenza'' of 1918-1921; viral infection of course, and was particularly nasty IN Europe, on a population-adjusted basis.

This is just another copy-bar for those who would whistle their personal behaviour past the graveyard of assorted retroviruses.

[Doctor Stochastic]

Exactly. The descriptions of the deaths during the various and sundry plagues in Europe do show that Yersinia Pestis was the culprit. (Of course, the plague that devasted ancient Athens is still a mystery.) There were also numerous descriptions of dead rats just before the Black Death arrived. (Perhaps the Christian association of cats with witchcraft was a problem; on the other hand, dogs can make good ratters too.)

Rome seemed to do well (in its heyday) because the city fathers concentrated on garbage removal and on having lots of water. General hygene helps controll all the plagues.