There was a bit about chicken pox vaccine on the CBC News a while back. As best as I can recall, some doc's (ped's included) are concerned about the length that the immunity lasts. Their concern is that without regular boosters, it may only last about 5 yrs, then possibly exposing the child or young adult to even further risk because usually chicken pox is worse at later ages. My ears usually perk up when I hear something about vaccines in the news. I truly understand their importance because I am a polio survivor. (I got it just before the vaccine became available.) My daughter has had all her immunizations. As I recall, when she was in Gr. 3 or 4, the Ontario gov't had province wide booster for the measles given at school. While there were not to be any side effects, she did get a bit of a fever afterwards. I also see that she gets a flu shot each fall. So far I think it has helped.