Discussion
This study found that the awareness campaign run by the CPAM did not improve the uptake of the dTcaP booster for adults aged 25 years. These findings may be inconsistent with existing literature on the effectiveness of patient reminders for vaccinations [Since this study was conducted in 2021, the effects of the COVID-19 pandemic may have limited the uptake of the dTcaP booster vaccine and corresponds with Rachlin et al., that found a 3% decrease for routine practices of other vaccinations in 2021 [As a health insurer, the CPAM is not entirely recognized among the French population for its preventive approaches, therefore, the awareness campaign may not have corresponded to the expectations of the participants. Some participants may not have paid sufficient attention to the information disseminated in the awareness campaign. In 2020, Plichon et al. studied the impact of the framing of a message and the arguments presented to explain changes in attitude towards vaccinations, intention to be vaccinated or to recommend a vaccination to relatives [The rate of vaccinated adults during the study period was low (16.7%). Over the last few years, vaccine hesitancy associated with negative feelings about the safety of vaccines has developed in France. According to Larson et al., in 2016 among 67 countries, 45.2% of the French population were skeptical about vaccine safety [Consultations with a GP was significantly associated with the uptake of the dTcaP booster vaccine. Patients recognize GPs as providers of credible information and they play a key role in individualized preventive healthcare actions, in which their influence on the acceptance of vaccines in children has already been shown [Regarding the strengths and limitations of this study, the originality of testing the impact of an awareness campaign on a large population via a randomized methodology posed a strength. However, we did not directly question the participants to identify the reasons why participants did not have the booster vaccine in the follow-up. For the INT group, we were unable to ascertain if information from the CPAM campaign was actually received and read, nor to assess their satisfaction with its content. The absence of an individual data collection on participants’ follow-up and healthcare pathways also did not allow us to take into consideration any possible confounding factors such as the professional setting (where some may have received a vaccination through an occupational medicine specialist), or to identify a routine follow-up provided by the GP.