The Talmud and Isaiah 53 metaphorically portray the Messiah as a leper, rejected and despised. See Leviticus 13:46. However, the Messiah's sickness isn't his own. It is our sickness in 3 ways:
First, the sickness of our sinful inclination drives us to reject him as if he were a leper. Second, he takes our spiritual sickness on himself and crucifies it with his body, beginning a process of remaking us in his image. Third, he takes away our physical sickness, enabling our healing and eventual resurrection to eternal life.