This is the first of a 3-part series of podcasts discussing childhood immunizations. This series will discuss vaccines, the routine immunization schedule in Canada, and common questions from vaccine-hesitant parents. This episode describes an overview of the immune system and how different kinds of vaccines work. This series has been developed by Kristen Timm, a Family Medicine resident at the University of Alberta, with the help of Dr. Sarah Forgie, Pediatric Infectious Diseases, University of Alberta.    Related Content: Podcast: Childhood Immunizations Part 2 and Part 3 (coming soon) Podcast: Invasive Meningococcal Vaccination in Canadian Children and Youth - CPS Practice Point Podcast