If I were you I would book the flight and hotel as soon as possible for 2 reasons: the first because prices are low and secondly because there are few people in the city for covid19. yesterday I was in Venice because I work there and there is no fear of getting the virus. for me outside the outbreak the risk of catching the virus is low, the same probability of being around the world especially if you go to naples or florence. the biggest problem with this virus is journalists and fake news.