What is Evidence-Based Medicine (EBM)

North America has experienced a resurgence of measles outbreak due to unprecedentedly low Mumps-Measles and Rubella vaccination coverage rates facilitated by the anti-vaccination movement. The objective of this chapter is to explore the new online public space and public discourse using Web 2.0 in the public health arena to answer the question, ‘What is driving public acceptance of or hesitancy towards the MMR vaccine?' More specifically, typologies of online public engagement will be examined using MMR vaccine hesitancy as a case study to illustrate the different approaches used by pro- and anti-vaccine groups to inform, consult with, and engage the public on a public health issue that has been the subject of long-standing public debate and confusion. This chapter provides an overview of the cyclical discourse of anti-vaccination movements. The authors hypothesize that anti-vaccination, vaccine hesitant, and pro-vaccination representations on the online public sphere are reflective of competing values (e.g., modernism, post-modernism) in contemporary society.