Ah. Good luck! That would be the reason the vaccine was developed. Good ol rules. I've successfully raised chicks without medicated feed and without the vaccine. Thing is, I introduce them to the soil outside on the ground very young so they get exposed to it over time and are not overloaded...
Why do you want the vaccine? It's really not necessary in my opinion. Medicated feed will cover all bases if you can get that. I hear that the vaccine is questionable too. If you do decide to get it, not sure where. Good luck.