The vaccine is one of medicine s greatest achievements, yet has continuously been met with scepticism and opposition. Many are surprised to find that the arguments against immunisation are practically unchanged for over 200 years. Authors on the subject tend to explain the phenomenon by particularities of the human mind or particularities of a given sociopolitical context, but none of them have looked closely at the particularities of the vaccine itself. The present inquiry aims to identify the properties which distinguish vaccines from other medical interventions to explain why they, specifically, remain controversial. It will be argued that vaccines have a particular mode of administration, a particular mode of distribution and a particular mechanism and effect. While certain traits are shared with other medications, it will be demonstrated how it s the configuration of features which inspire vaccine controversies, where any single aspect might have varying importance. This configuration of properties is inherent to the vaccine and thus universal, but also subject to a variety of interpretations, depending on context. Many such interpretations are considered here in a review of the main arguments against vaccination. Through this analytical review, the following thesis is also an attempt to render vaccine opposition comprehensible. Finally it aims to explain the persistency of the phenomenon, by pointing to the fundamental concerns which are expressed through vaccine opposition. These reflect continuing debates in modern society and are concerns about the body, concerns about the relationship between state and individual and concerns about technology and human intervention.