Unlike coronavirus, most scholars agree on the cause of bubonic plague. Bubonic plague is caused by a bacterium, Yersinia pestis. However, the culprits anthrax, hemorrhagic viral fever, and louse-borne typhus have also been credibly proposed, according to Andrew Noymer, [associate] professor of public health at UC Irvine.
The Black Death: What Bubonic Plague Reveals About COVID-19 Coronavirus Pandemic
MedicineNet, March 19, 2020
March 19, 2020