The 2 original shots are considered "fully vaccinated". I won't do boosters, I don't trust them. If those coming from across the pond do not need the boosters, neither do I. We were told the 2 original shots were sufficient. We sailed Equinox in May, My friends had the boosters. My son, daughter-in-law and I did not. THEY got covid and a really bad case of it. No boosters for me.