Stopping the people won't help much, the Bubonic Plague generally isn't spread from person to person but from rat to rat via fleas which only go after humans on

Stopping the people won't help much, the Bubonic Plague generally isn't spread from person to person but from rat to rat via fleas which only go after humans once all the rats are dead of the plague. Several cities in the 14th century plague did try to quarantine themselves without much success. The pneumatic version of the plague which cropped up in some northern areas could be spread directly from person to person and, IIRC, the septic version too via the fleas that typically prayed on humans. But those caused a minority of the plague deaths.