For instance," said Alan, "we're now learning that the smallpox pandemics of the Middle Ages, not the plague, mind you, but smallpox, left generations of people with a rare genetic defect that protects them against infection by HIV, the virus that causes AIDS. We estimate that approximately one percent of people descended from northern Europeans are virtually immune to HIV infection.
In "Blowback," author Brad Thor discusses the historical impacts of pandemics on genetic evolution. Alan highlights how the smallpox pandemics of the Middle Ages have inadvertently shaped human genetics, leaving a legacy that protects certain individuals against modern diseases. Unlike the plague, smallpox led to a unique genetic adaptation among descendants of northern Europeans.
This fascinating observation indicates that about one percent of these individuals possess a rare genetic mutation that renders them nearly immune to HIV, the virus responsible for AIDS. This connection underscores the long-lasting effects of past pandemics on contemporary health and genetic resistance.