Vagana was selected for the New Zealand team to compete in the end of season 1999 Rugby League Tri-Nations tournament. In the final against Australia he played on the wing and scored a try in the Kiwis' 22-20 loss. In April 2002, Vagana became the first Bulldogs player since 1942 to score five tries in a match. That season he was the League's top try-scorer. He signed a two-year contract with NRL club South Sydney, starting in 2007, expiring at the end of 2008.