The health pass is limited in its effectiveness, as although it has been effective in getting the complacent to book their vaccination appointments, it does not address all barriers to vaccination. For many people, the health pass had little effect, because the elderly, the poorest and the most marginalized do not engage much with the activities covered by the pass, such as eating out in restaurants. For instance, as of 12 October 2021, only 86% of over-80 year olds had been fully vaccinated2.
The health pass has encouraged vaccination of many who were hesitant or reluctant, but it has not reduced hesitancy itself. A survey from September 2021 found that 42% of vaccinated people were still reluctant or had doubts about the vaccine at the time of their first dose7. More importantly, the share of vaccinated people with doubts about the vaccine increased from 44% to 61% after the health pass was implemented (Fig. 1).
France remains a very vaccine-hesitant country, and this hesitancy does not seem to have decreased much as a result of either the COVID-19 health pass or mandatory infant vaccines, which were extended in 2017. One of the rationales for extending mandatory infant vaccination was that such a strong gesture would signal to the public the complete faith of authorities in these vaccines13. Although this policy did not elicit a public backlash, trust in vaccines does not seem to have significantly improved and France is still a very vaccine-hesitant country, as demonstrated in earlier stages of the pandemic4,5,14.
There is little to suggest that the health pass has convinced many skeptics about the benefits of this vaccination15 and there remains a small but considerable proportion (around 5–10% of the population) who have decided not to take the vaccine for COVID-197. Vaccinating people who are hesitant or reluctant has potentially negative consequences, which can reinforce mistrust of institutions and of the healthcare system3,8,16.
A feeling of coercion while being vaccinated can cause a nocebo effect, in which negative outcomes occur because of a belief that the vaccine will harm them. The nocebo effect might explain why, in our survey, the share of vaccinated people who said they suffered side effects from the vaccine increased from 34% among those who had their first dose in June to 57% of those who had their first dose in August, after the health pass was implemented.