Nyce, Jonathan W.2019-12-022019-12-021996-04-18International Publication # WO1996011280A1http://hdl.handle.net/10342/7558Disclosed are attenuated viruses, not naturally occurring, that contain one or more additional methylation sites in the genome of the virus compared to the corresponding wild-type virus. Preferably, the methylation sites are added into the genome of the virus by introducing an additional CG segment into the genome by means of a silent mutation. The attenuated viruses are useful for producing an immune response, including both the production of antibodies in animals for diagnostic use and the induction of protective immunity in a subject. Pharmaceutical formulations and methods of making the attenuated viruses are also disclosed.en-USvirologymodificationimmunologyPatent