I know that Marek's vaccinations should be given in the first few days of life (day old chicks usually, but I hatch some smaller chicks and the breeders recommend day 2 or 3 for them), and that one they are 'exposed' to the virus it essentially negates the effectiveness of the vaccine. That being said... I've found some chicks that I'm interested in but the breeder does not offer vaccinations. Just wondering of the effectiveness of vaccinating these chicks once they arrive. They're bantams so I probably would've waited to vaccinate them on day 2 or 3 anyway and figure that their odds of exposure are low since they're being delivered via USPS. The breeder is only 1 state away and I have access to a facility in the town that they'll be delivered to (I live rural and live chicks always arrive a town away). Marek's isn't common (meaning not many flocks die from it here, I know most pros say marek's is 'everywhere), especially in the urban area that they'll arrive in. Anyway, I have the vaccine on hand and the plan is to go forward with vaccinating the imports. I guess I'm hoping for reassurance that there is a possibility that the vaccine will take. I lost a small flock to Marek's a few years ago and vaccinate everything ever since.