What Is a Vaccine? By Vincent Iannelli, MD / December 24, 2018 / active immunity, adjuvants, antigens, Edward Jenner, eradicated diseases, herd immunity, incubation period, live vaccines, passive immunity, placebos, quarantines, saline placebo, shedding, titer testing, titers, vaccine definitions, Vaccine Education, vaccine glossary, vaccinia, variolation A vaccine stimulates your immune system, providing active immunity and protecting you from disease. Share this:FacebookTwitterRedditPrintLinkedInPinterestEmailTumblrWhatsAppLike this:Like Loading...