Topics in Policy Analysis (Half-Term): Vaccination: Epidemic Dynamics, Policy and Vaccine Hesitancy

Vaccination is one of the most powerful tools in global health. However, vaccines are arguably much less deployed than they should be, due to a combination of economic and biological constraints, as well as the rising trend of vaccine hesitancy Here, we review the biology of vaccines and their impact on infectious disease dynamics, focusing especially on the key concept of herd (community) immunity. We then use case studies to discuss the successes and limitations of vaccination against human diseases, drawing general implications about their optimal future deployment.