Thanks to the ACA, you can buy comprehensive health insurance for a low price, assuming you're young.
If I were the person fielding your request, I would wonder if you were having second thoughts about medicine, didn't really want to come here, or were just an anxious person in general.
COVID-19 will be everywhere. Unless you have a stable job that allows you to work from home, there is no real way to predict at this time whether you will be safer where you are or where your program is.