Fortunately those who survived that period already had protective genes in place and those were passed on to us. Alas, those not living in Europe, the Middle East, North Africa, China or Central Asia were never affected by the Black Plague. We don't know if they are immune or not, but they probably aren't.
If something interfered with tetracycline production and distribution around the world the Plague would kill billions in just a few years.
Folks shouldn’t get so smug ~ at a minimum 4 billion people have no natural immunity to Yersinia pestis (Black Plague).
And it wasnt so long ago that the Spanish Flu knocked off a few millions
Nature has a way of keeping the worlds population regulated it seems.
These liberals make me laugh - its their duty to take God’s business into their own hands.
Unless, of course, you take into account that Yersinia pestis is a bacteria that simple penicillin takes out.