Do you require the vaccine to be part of your 7 day Rome tour ?
If you are asking about RS tours, look at this -- https://www.ricksteves.com/tours/coronavirus-faq
Will I need a COVID-19 vaccination to join a tour? And what about boosters?
Yes, to participate in a Rick Steves tour we require all tour members to be fully vaccinated (received all recommended doses in their primary series) and up to date with booster doses (when eligible). Get more details about staying up to date on COVID vaccines from the CDC.