Vaccine Hesitancy in the French Population in 2016, and Its Association with Vaccine Uptake and Perceived Vaccine Risk-Benefit Balance

"It is essential to improve understanding of individuals considered vaccine hesitant, as they represent the first target of public health measures to improve immunisation coverage."

Vaccine hesitancy (VH) is prominent in France. To identify vaccine concerns early, quantify their prevalence, and evaluate the impact of strategies designed to address these concerns, measuring VH and following its evolution over time is necessary. The goals of this study were: (i) to estimate the prevalence of VH in parents of children, parents of adolescent girls, and elderly people, (ii) to determine VH's socio-demographic correlates, (iii) to understand in each concerned sub-group which specific vaccine-related behaviours and perceptions VH captures, and (iv) to study associations between VH and both self-reported behaviours and the perceived risk-benefit balance (RBB) for the measles, hepatitis B (HBV), human papillomavirus (HPV), and seasonal influenza (SI) vaccines. These 4 vaccines have a non-optimal coverage in their target groups (90% for HBV at 24 months of age in 2016, 20% for 1 dose HPV in 2015, 80% for 2 doses of measles in 2016, and 51% for SI in the elderly during the 2015/16 season) with respect to French public health objectives (95% for all vaccines, except 75% for SI in the elderly).

A Computer Assisted Telephone Interview (CATI) survey was conducted between January and July 2016 in mainland France with a representative sample of French people aged 15-75 years. The vaccination section of the 2016 survey was designed to evaluate perceptions and behaviours in 3 population sub-groups: parents of children aged 1-15 years (PC), parents of adolescent girls aged 11-15 years (PAG), and individuals aged 65-75 years (EP). The PAG group was part of the PC group, and therefore analysis of the latter included the former.

The questionnaire included 3 questions adapted from the Strategic Advisory Group of Experts (SAGE) on Immunization group's definition of VH: (i) "Have you ever refused, (for your child (PC/PAG)/for yourself (EP)), a vaccine recommended by your physician, because you considered this vaccination dangerous or useless?" (ii) "Have you ever delayed a vaccine recommended by your physician, (for your child (PC/PAG)/for yourself (EP)), because you hesitated over it?", and (iii) "Have you ever had a vaccine, (for your child (PC/PAG)/for yourself (EP)), despite having doubts about its effectiveness?" Notions of effectiveness and safety were included in the wording of the questions to rule out reasons for vaccine delay, which were not related to doubt or opposition to vaccines (e.g. child having a cold, forgetting a vaccine appointment). In each sub-group, people were asked questions about the vaccine(s) specifically recommended to them or their children. Moreover, for each vaccine studied, 5 other questions were asked.

A total of 3,938 parents, including 959 girls' parents, and 2,418 EP were interviewed. Regarding vaccination of their children, the estimated prevalence of VH among PC was 46% (95% confidence interval (CI): 44-48); among PAG, it was 48% (95% CI: 45-51). Estimated VH prevalence was 35% (95% CI: 33-36) among EP. Higher estimates were associated with high education level, children's age (10-15 years), and, for the elderly, poor perception of health status. VH was associated with uncertainty about and/or an unfavourable perception of vaccines' RBB for the 4 vaccines and with lower self-reported vaccine uptake, except for HPV vaccine in girls. (The researchers write, "If we consider that self-reported HPV vaccine uptake was 17% in adolescent girls and that only a total of 48% of PAG were vaccine hesitant in our survey, this suggests that our VH definition, which focused on doubts about vaccine safety and effectiveness, was too restrictive to capture all parents' HPV vaccine perceptions.") The most favourably perceived vaccine by parents (PC and PAG) was for measles (45% had a very favourable perception of the vaccine's RBB).

The researchers discuss the findings, noting that VH is also present among European vaccine providers, both for patients and for themselves. For example, during recent controversies in France about the HPV vaccine, some physicians put forward arguments against its use. According to the researchers, "There is a real need to address this loss of confidence, as health professionals have a major role in their patients' decision making about vaccination." They point to a 2015 review of strategies for addressing VH showing that the most effective interventions were multicomponent and dialogue-based interventions, tailored to specific populations and addressing specific concerns.

In conclusion, the researchers call for further research to confirm these results, to study the association between VH and vaccine uptake for other vaccines, and to design and validate measurement tools to monitor VH over time in order to help evaluate interventions implemented to address VH.