Vaccination is often described as one of the greatest achievements of public health. While the scientific and medical consensus on the benefits of vaccination is clear and unambiguous, a growing proportion of Canadians is sceptical about vaccination. In Canada, fewer than 5% of parents refuse all vaccines for their children, but up to 35% are hesitant about vaccination. Vaccine-hesitant (VH) parents may refuse some vaccines, but agree to others; they may delay vaccines or accept them according to the recommended schedule, but feel unsure about their decisions. Risk perception is a well recognized determinant in vaccine decision making. Two dimensions are usually emphasized: perceived risks of vaccine-preventable diseases can foster vaccine acceptance whereas perceived risks of vaccines can contribute to vaccine refusal. Sadly, this rational approach to risk perception and health decision-making does not reflect reality as other factors come into play. Vaccination decisions are much more linked with how people feel about the facts than to the facts themselves – even if they do correctly understand these facts. Judgements about risks are intuitive, automatic and often unconscious. Many studies have also shown that lack of trust in vaccine information, more than lack of vaccine information in itself, is associated with vaccine hesitancy. Lack of trust is sometimes associated with perceived lack of balance in the information transmitted by healthcare providers and public health authorities. Further, individuals are “cognitive misers”, collecting only as much information as they think is needed to reach a decision.
Using results of different studies conducted among Canadian parents of young children, this paper focuses on risk perception and its impact on vaccination acceptance, hesitancy and refusal. We will highlight that risk perception about vaccines among lay people are based on an “uncertainties and ambiguities” approach where doubts remain even in the face of empirical evidence. Individuals assess vaccine risk in different and unique ways that reflect their cultural, emotional, social and political worlds. In the context of a globalizing mass media, the awareness of certain risks may have changed, but people continue to understand and negotiate risks in localized contexts