Covid etiquette

At least 50 percent of U.S. adults have been fully vaccinated. That leaves a high number of people who are either reluctant or who are adamantly opposed. For a variety of reasons, we are operating in a world where we don’t know who has had the vaccine and who has not. Depending on the situation, there may be a need to know. That, of course, raises questions about when it is appropriate to ask if someone has been vaccinated and how do you ask?