alot of people say that injecting your birds they wont perform as good .. as youngings or yearlings .. i know a few top fanciers that inject for it and are winning steady.. but i think its very sore on the birds because i inject for paramyxo twice when there young and if i was to do paratyphoid .. thats 3 injections and its a bit much .. last year i got a few birds in and within days my youngbird loft was rife with it .. this year ive decided against vaccinating .. but if i ever have a problem with it again i will