I am immunosuppressed (and get COVID vaccines every 6 months; the RSV vax, etc) and was told by my Rheumatologist that persons who are immune compromised carry the virus longer than others. This means the wait-time to not be infectious is typically longer, so that the immunosuppressed person can shed all of the virus and not be infectious to others. I have had COVID twice (Paxlovid is a miracle worker for me!); RSV turned into pneumonia and landed me in the hospital. I am 69, and very cautious. When home I watch other for symptoms and slip on a mask (or move to a diffferent location if possible), and keep my hands washed regularly and carry antiseptic wipes everywhere. When traveling, I wear the N95 mask in the airport and on the plane because of the number of people & enclosed spaces…plus on cruise tour buses and am vigilant of others’ coughing etc... I don’t want to end up in the hospital, so take as many precautions as possible, while still mostly living my life as I did pre-pandemic. Your friend could still be shedding the virus; if it were me I would steer clear for another week.