Does anyone vaccinate their chickens? I know you are not supposed to mix non vaccinated chickens with vaccinated ones. However my vaccinated stock is over 1 year old and some over 2-3 years old. Would these birds be a threat to new non vaccinated pullets after a year old? Is it wise to vaccinate all birds you breed yourself? I can vaccinate all my birds from a day old for IB and Newcastles disease in the drinking water, but dont like the idea of injecting my day olds for the rest. Does anyone do this? At the moment l have non vaccinated birds with the vaccinated (did this before l was aware of the problems) and we dont seem to have a problem with health. Would like to know of anyone's experience with this.