Vaccine criticism: Presence and arguments on French-speaking websites.

OBJECTIVE: To evaluate the presence of vaccine criticism on the French Web and to analyze strategies and arguments used by opponents of vaccination.

METHODS: The most frequently used keywords associated with the terms "vaccination" and "vaccine" on Google.fr in September 2013 were identified and searched for individually on Google.fr. The links presented in the first three pages of results were reviewed to identify the most frequent providers of information. The proportion of critical content was determined by website type and a content analysis was performed.

RESULTS: The main preoccupations about vaccination were general concerns; <1% of searches were guided by negative keywords. Institutional websites, healthcare websites, news websites and anti-vaccine websites were the most frequent providers of results. The proportion of anti-vaccine websites among the results was 11% for a neutral search and 24% for a search guided by negative keywords. Critical content was observed in other types of website. Six major strategies and categories of arguments used by opponents of vaccination were identified: the manipulation of science, the use of shocking images and an appeal to emotions via testimonies, a general vaccination conspiracy, the individual's freedom of choice not respected, an unnatural act and a negative benefit/risk balance.

CONCLUSION: It seems important to monitor online vaccination debates, to develop an institutional presence that meets the needs of Internet users and to help them develop a critical view.