What’s the Difference Between the MMR and MMR-II Vaccines? By Vincent Iannelli, MD / April 7, 2019 / arthritis, diluents, high passage virus, History of Vaccines, HPV-77, Maurice Hilleman, MMR-II, placebos, RA27/3, rubella, saline placebo, twins, vaccine safety systems The MMR-II vaccine is an improved version of MMR, with a better rubella component. Share this:FacebookTwitterRedditPrintLinkedInPinterestEmailTumblrWhatsAppLike this:Like Loading...