How old are they? You say they are new-born but have been treated with Corid and you are feeding them so I question just how old they are. Were they hatched in an incubator or with a broody hen? What shots were you thinking of giving them? Could you please explain a bit on how and why they were treated with Corid? Were they fed Medicated Feed or was Corid put in their drinking water? Do you have any history of disease with your flock?
I don't vaccinate my chicks for anything but i don't have a history of disease with one exception. I had some chicks with a broody hen come down with Coccidiosis once when the weather was ridiculously wet for a long time so i know I have Coccidiosis in my flock. I manage that with my brooder-raised chicks by feeding my chicks dirt from the run every three or four days while hey are in the brooder and keeping the brooder dry. That way, by the time they are ready to leave the brooder they have developed immunity to that strain of Coccidiosis. If they are with a broody hen and the weather is not ridiculously wet they develop that immunity on their own.
Some vaccines need to be given before they come into contact with other chickens and they need to be isolated from other chickens for two to three weeks to give the vaccine time to set up. If you give them the Coccidiosis vaccine you do not want to treat them with Corid or feed them medicated feed, that wipes out the vaccination. Some can be given later.