In Europe, several events in recent decades have had a significant impact on vaccine acceptance. This was seen in France during the debate in the 1990s over the hepatitis B vaccine and its supposed link to multiple sclerosis; more recently, there was also controversy over the 2009 influenza A(H1N1) vaccine. The UK has experienced a similar phenomenon with the spread of false information claiming a link between measles vaccination and autism, which led to an upsurge in measles outbreaks. These events were followed by a decrease in vaccine acceptance and a concomitant rapid rise in vaccine hesitancy, defined by the WHO as postponing or refusing safe vaccination despite its availability.
What is the current situation and what are the underlying determinants of vaccine hesitancy? What are the potential routes for reviving confidence in vaccination? The authors of the article published this month in the journal Vaccine  offer some answers to these questions.
3 questions for: Sophie Vaux, Infectious Diseases Division - Oriane Nassany, Prevention and Health Promotion Division - Arnaud Gautier, Data Support, Processing and Analysis Division, Santé publique France.
It’s right that “mistrust” of vaccination, which covers a range of attitudes on the spectrum between pro- and anti-vaccination, is difficult to measure: various studies have provided estimates for specific populations such as the elderly or parents of young children, but there is no standardised indicator to use as a measure in the general population.
One way of approaching this hesitancy is not to ask the population about their mistrust, but instead whether they accept the principle of vaccination. Acceptance of this has been monitored for more than 20 years through the Santé publique France Health Barometer using the question: “Are you in favour of vaccination in general?”.
This system of repeated surveys draws on large samples (generally between 15,000 and 25,000 respondents) that are rigorously selected (probability sampling). The Santé publique France Health Barometer allows us to monitor changes in the health-related habits and opinions of the French population, both in mainland France and, from around a decade ago, in the overseas departments and regions. The results of these surveys help us to evaluate our preventive actions and also to adapt our messages and information campaigns. This means that the data collected is valuable to all those involved in the field of public health and, in this case, in promoting vaccination.
Overall vaccination acceptance decreased from 89.9% in 2005 to 61.2% in 2010, following the 2009 influenza pandemic.
Acceptance subsequently increased (78.8% in 2014) then fluctuated over the following years and increased again in 2020 (80.0%) and 2021 (82.5%). The latest data, not published in this article, show a sustained increase with acceptance reaching 84.6% in 2022. This means that a rise in vaccination acceptance was observed during the COVID-19 crisis.
Regardless of the year, acceptance was higher for people with high incomes, those with higher levels of education, and those who did not live alone. In 2021, for the first time, acceptance was higher among adults aged 45 and over (particularly those aged 65 and over, with 85.9% acceptance) than among 18–24 year-olds, and it was higher among retired people than among active people; these groups were largely those who benefited the most from the COVID-19 vaccination.
The overall increase in acceptance in recent years should not obscure the trend of growing differences in acceptance across social and economic strata. In 2021, acceptance was low among people with the lowest levels of income and education, and well below the rates seen for these groups before 2009.
The article showed that not only does vaccine acceptance no longer reach the level observed prior to 2010, but also that in 2021 the gap between those with the lowest incomes and those with the highest was wider than before 2010. In order to maintain the rise in vaccine acceptance by reducing social inequalities in health, the priority is to develop vaccination promotion strategies that take the social gradient into account.
During European Immunization Week 2023, numerous strategies were launched targeting the least affluent populations, such as vaccination catch-up appointments, promotion of hepatitis B vaccination, vaccination status checks, raising awareness about human papillomavirus (HPV) vaccination and vaccination promotion in general.
Furthermore, Santé publique France has developed numerous resources about vaccination, providing information that is easy to understand and accessible to the general public. For example, the “vaccination-info-service” website has been developed in two versions: one for healthcare professionals and another for the general public that features clear, illustrated summaries of information. In order to reach as many people as possible, the agency also produces resources targeted at more specific populations. Videos on some of the diseases that vaccination can prevent (measles, hepatitis, chickenpox, whooping cough, etc.) have been published in French sign language and several brochures have been adapted into an “easy read” format.
The HPV vaccination campaign, which just started in secondary schools in September 2023, is part of the same approach. The campaign aims to improve low HPV vaccine coverage, but also to increase HPV vaccine acceptance by reducing social inequalities in access to provisions of care and prevention.
In addition, the Provence-Alpes-Côte d’Azur (PACA) Regional Office (Regions Division) of Santé publique France collaborated with the PACA Regional Health Observatory to conduct a study on vaccination hesitancy among pregnant women. This study demonstrated the impact of an educational strategy that consists of carrying out motivational interviews in maternity wards to boost confidence in vaccines (see Box – Motivational interview to reduce vaccine hesitancy among mothers).
These examples show our continued efforts to identify and assess promising interventions in order to increase vaccine acceptance in the population, along with our work to reduce the widening gaps observed between people of different socio-economic groups.
 Vaux S, Gautier A, Nassany O, Bonmarin I. Vaccination acceptability in the French general population and related determinants, 2000-2021. Vaccine. 2023 Sep 4:S0264-410X(23)01018-6. doi: 10.1016/j.vaccine.2023.08.062. Epub ahead of print. PMID: 37673718.
Motivational interview to reduce vaccine hesitancy in mothers
Motivational Interviewing (MI) is a two-way conversational strategy that strengthens an individual’s motivation and commitment to change their behaviour. MI tailored to vaccination has been demonstrated to be effective in Quebec among parents of newborn babies in maternity wards. The MOTIVAC-MATER trial (1) applied this approach to France with the aim of testing whether it would be feasible to carry out MI with parents in maternity wards and whether this approach could reduce vaccine hesitancy (VH) in mothers and boost their intention to vaccinate their children at 2 and 12 months.
A multicentre, parallel group, randomised, controlled study comparing the impact of MI with issuing a vaccination brochure (control) was conducted in two maternity wards in the Provence-Alps-Côte d’Azur region. The participants were mothers who had just given birth. In each group, participants completed self-administered questionnaires before MI or brochure (T0), after MI or brochure while still on the maternity ward (T1) and approximately 7 months after discharge (T2).
Out of 733 mothers who participated in the study, 656 (89%) completed the T0 and T1 questionnaires and 407 (56%) completed the T0, T1 and T2 questionnaires. At T1, MI was significantly associated with a 33% reduction in the mothers’ VH score and an 8% increase in the intention to vaccinate babies at 2 months of age. These effects were maintained at 7 months. The satisfaction rates of the mothers who took part in the interview were higher than 95% on all indicators, including the choice of the time of intervention.
Motivational interviews had both short- and medium-term impacts on vaccine hesitancy among the mothers, the intention to vaccinate their newborn babies, and satisfaction with the programme. These results demonstrate that interventions with parents in the maternity ward are feasible and effective, and argues in favour of rolling out the intervention on a larger scale to improve vaccine confidence.
The project is currently being incorporated into the Santé publique France directory of effective or promising interventions in prevention and health promotion.
(1) - Verger P, Cogordan C, Fressard L, Gosselin V, Donato X, Biferi M, Verlomme V, Sonnier P, Meur H, Malfait P, Berthiaume P, Ramalli L, Gagneur A. A postpartum intervention for vaccination promotion by midwives using motivational interviews reduces mothers' vaccine hesitancy, south-eastern France, 2021 to 2022: a randomised controlled trial. Euro Surveill. 2023 Sep;28(38):2200819. doi: 10.2807;1560(7917):ES.2023.28.38.2200819. PMID: 37733238; PMCID: PMC10515496.