 Vaccari won his first cap in 1991 against Namibia in Windhoek (defeat 7–17, although he scored a try at his debut); he went on playing three consecutive editions of the Rugby World Cup (1991, 1995 and 1999).Vaccari was part of the Italian team that won for the first time the 1997 FIRA Trophy against France.His most significant international performance was the 1997 FIRA Trophy Final, played in Grenoble, a 40–32 win which meant the first Italy win over France.