My business can run without me for more than a month.You must have very good sick leave. Most people would experience impact to their employment and therefore income if they were dealing with months of symptoms. Given the US labor situation, the country can't afford people being unavailable or restricted in their availability or performance for even months.
The cognitive symptoms will be an interesting one to watch on top of the stamina issues. People could still be showing up, but the rate of mistakes and productivity could rear their heads. How many mistakes, and how serious of mistakes are you willing to tolerate from your employees, before you have to start thinking about options? How much slower can they work?
Not counting investments etc I have a liquid emergency fund large enough to cover 1.5 years of living expenses without my family having to reduce their quality of life.
I have life insurance if covid killed me.
I call it personal responsibility.