Better that than 3/4 of your workers off sick at the same time because those 1/5 came in to work sick and spread it, I suppose. Though maybe that isn't how it works, and we'll find out in the US since people will generally have to work sick here whether they want to or not (due to our sick leave policies and health costs).
"Coronavirus: British government makes contingency plan in case one fifth of UK workers 'off sick at same time' "