Ethical Chickens are VACCINE-FREE
 
 
Vaccines contain live or, dead organisms which, may not be indigenous to our environment. Vaccines also contain carriers and preservatives (mercury, aluminum) and are often manufactured with human fetal tissue, reptilian tissue, K-9 and other foreign cells. Chicken vaccines can be administered either by drinking water, injection, by drops on their heads or, administered through the egg, while the chicks are in their incubators (before hatching). Remember, eggs are very porous. Excessive vaccine exposure and consuming chickens that have been vaccinated can lead to vaccinosis or, even worse.
Vaccinated chickens are NOT Ethical Chickens and, certainly NOT Kosher.
In nature, chickens (birds, Gallus) do not administer single or multi-specie vaccines to each other. All the antibodies that baby chicks need come from their own parents such as the mother hen and their local environment through  beneficial micro-organisms.  We do not want to poison our chickens,  and we do not want to eat chickens that have been administered poisons or foreign cells from other animals, or worse. It seems unethical to us, and it may defeat the whole purpose of raising nutritionally superior poultry. 
Farmers who buy their day old baby chicks from commercial hatcheries, are buying chicks which have already been vaccinated. Some farmers then make the claim "WE never vaccinate our chickens" which is probably true, especially since it's already been done at the hatchery. Hatcheries do not want to get shut down, or be known for transmitting avian diseases. Of course they vaccinate the baby chicks. There are regulations in place especially, for shipping baby chicks across state lines. 
Ethical Chickens have naturally strong immune systems. They get all their natural antibodies from their mother hens and, their environment. Ethical Chickens are beneficial to our environment and, they come from personal, closed flocks. They are naturally disease resistant with very strong immune systems.