The present invention relates to Lawsonia intracellularis vaccines and methods for protecting against and diagnosing L. intracellularis infection. The products and processes of the invention are attainable, in part, as the result of an improved method for cultivating large scale supplies of L. intracellularis, including both a novel isolate of L. intracellularis of European origin and a method of preparing a lyophilized product containing the attenuated European isolate as vaccine product.