A bed full of fleas.
Folger Shakespeare Library.

There were several years during Shakespeare's time in London in which the plague was severe enough to close the theatres: 1582, 1592 (15,000 deaths), 1603, and 1607.

The Elizabethans had no idea that the plague was spread by fleas that had lived on rats; though there were many "cures" for the plague, the only real defense--for those who could afford it--was to leave the crowded, rat-infested cities for the country.

A preservative against the pestilence

Take yarrow, tansy, featherfew, of each a handful, and bruise them well together, then let the sick party make water into the herbs, then strain them, and give it the sick to drink.

Another [more palatable] remedy for the plague

Take of sage, rue, briar leaves, elder leaves, of each a handful, stamp them and strain them with a quart of white wine, and put thereto a little ginger, and a good spoonful of the best treacle, and drink thereof morning and evening.