The present invention provides improved methods and compositions for producing oocysts. The oocysts produced according to the invention find use in the manufacture of vaccines. In preferred embodiments, the present invention provides methods and compositions for the production of Eimeria oocysts. Vaccines containing Eimeria oocysts, sporocysts and/or sporozoites produced according to the present invention may be used to immunize birds against coccidiosis either in ovo or post hatch.