@Susan378,
You have very lovely listings. If you decide to request COVID-19 vaccinations of your guests, are you also going to require it from your cleaner, property manager, co-host, and disclose if you've received the vaccination? I ask, because you stated in your listing sometimes you are on site, and I assume that you have someone cleaning and maintaining the property when you're away. It's likely that each of you will go into the rentals at some point.
For my listings in St. Lucia, at some point the government will probably make vaccination a requirement for entry onto the island. In my Atlanta apartment, I am sure that neither the county, state or federal government will allow vaccination to be a requirement to rent a space. However, I can see the CDC and Homeland Security departments requiring it as a US entry requirement.