More than a decade ago, the WHO published the 3Cs model of vaccine hesitancy (confidence, complacency and convenience). It attempts to boil down the various drivers of vaccination acceptance into three key areas. Several other approaches have been considered over the years, but the European Centre for Disease Prevention & Control (ECDC) uses a 5C model to describe the factors shaping vaccination acceptance.
The ECDC is responsible for strengthening Europe’s defences against infectious diseases. As an EU body, it collects data from Member States, identifies health threats and publishes expert advice.
We asked ECDC experts how the agency is supporting European countries and healthcare professionals in protecting the public against vaccine-preventable diseases. In particular, this article asks what the 5Cs are and how they can be applied. (This is the second of two articles about ECDC support for vaccination acceptance.)
Read the first article here
VaccinesToday: The ECDC’s approach is founded on the 5Cs. This may be new to some readers. Others may have come across the 3Cs, 4Cs, 7Cs or 5As. Is this theoretical issue ‘settled’ for the moment i.e. are the 5Cs here to stay?
ECDC: As you state, several models from social and behavioural science have been used to describe vaccination acceptance and uptake. All of these have their own specific strengths and limitations; none is intrinsically better than another. In addition to the models that you mention, there is also the WHO Behavioural and Social Drivers model of vaccination, which was, for example, part of a survey tool implemented across EU countries during the Covid-19 pandemic.
In the ECDC report [on tools for promoting vaccination acceptance and uptake], we work with the 5Cs Model which we think provides a structured and intuitive, but not too complicated, way of understanding the core areas that impact upon an individual’s willingness and readiness to get vaccinated.
This doesn’t mean that the 5Cs is necessarily ‘the best’, but rather that it works well with the particular target audience of the report, who are predominantly epidemiologically-oriented vaccination experts working at public health institutions.
What are the 5Cs?
The model is based on five components that influence vaccination intentions and behaviour: Confidence, Complacency, Constraints, Calculation and Collective responsibility. At least in English, the 5Cs are relatively easy to remember!
For example, Confidence refers to an individual’s trust in the safety and effectiveness of vaccination, trust in the professionals and policy-makers who recommend vaccination, and trust in the health authorities and health systems that provide them.
Complacency refers to an individual’s perceived risk of a serious outcome arising from contracting a given disease.
Constraints refers to the perceived or actual barriers to vaccination faced by an individual. These constraints can be both psychological and structural; for example, referring to a person’s self-efficacy or perceived ability to get themselves vaccinated, access a booking system, or take time off work to go to a vaccination appointment.
While the 5Cs Model is predominantly focused on the psychological antecedents of vaccination, it is clear that sub-optimal vaccination uptake occurs due to multiple other factors.
For example, Constraints include structural factors that are beyond an individual’s control, such as how easy it is to get vaccinated practically, as well as the extent to which they can access appropriate information.
How might this approach be applied to addressing misinformation? What is the ECDC doing on mis/disinformation at the moment?
Similar to quantitative and qualitative survey data, data from social listening, including social media sources, can be collected and analysed based on the 5Cs model in order to diagnose barriers and facilitators of vaccination, and to inform the development of evidence based and tailored interventions.
The 5Cs model can identify if there is a problem with confidence about a particular vaccine in a population, which may point to the influence of mis- or disinformation. Further research might be needed to specify what that mis/disinformation is, how it is affecting people’s perceptions of the vaccine (or of the disease), and what might be done to address it.
ECDC’s work in this area also includes a training on how to address online misinformation about vaccination. This online course pulls together research in the fields of psychology, social behavioural science, and communication, and provides evidence-based strategies and tools to address online vaccination misinformation.
We are also working to establish systems that enable the understanding of public perceptions and narratives, using social listening and social media listening. This applies to vaccination-related narratives as well as infectious diseases more broadly.
For busy healthcare professionals (HCPs), are there actionable approaches they could quickly learn and apply to increase vaccine uptake? We have previously written about the ARM approach (Act, Recommend, Motivate), AIMS (Announced, Inquire, Mirror, Secure), and a four-point approach to Empathetic Refutational Interviewing developed by the EU-funded JitsuVax project. Is there a role for ECDC in distilling these down to enhance their usability?
ECDC has also done training for countries on motivational interviewing (training workshop in Bucharest, December 2022), which can also be effective in opening up a discussion with patients/caregivers. Different approaches may be effective in some populations and settings but not in others.
If there is one point that is cross-cutting, it is that people need to feel that they can ask questions to their HCP without being labelled (e.g. as ‘vaccine hesitant’), and also that their HCP is listening to them and their concerns – not dismissing them. Empathy by HCP is therefore of core importance in facilitating vaccination acceptance and uptake.
It is also important to support healthcare providers with information and materials so they can address the concerns that their patients may have around vaccination. ECDC has developed materials in this area for frontline healthcare providers, including an e-learning launched early 2025 that is available on the ECDC learning portal. This course focuses on vaccination acceptance and includes materials with key facts on vaccination that can help the HCP address commonly asked questions.
Further, during the two-day workshop held in October 2025 with six countries, on promoting vaccination acceptance and uptake, one of the modules focused on experiences and tools for supporting healthcare professionals in their conversations on vaccination with patients. This recognises the importance of such topics. In the module, approaches such as MI (motivational interviewing) and the JitsuVax project’s ERI (Empathetic Refutational Interviewing) were mentioned, as well as country examples on approaches and tools to support healthcare providers.
Are there inspiring examples of social and behavioural interventions that have been effective in reaching pockets of undervaccinated groups?
The ECDC operational report includes a library of some 25+ inspirational national and sub-national intervention examples, classified by the 5Cs Model.
For example:
- An intervention to support open dialogue between healthcare personnel and parents ahead of childhood vaccination addressing Confidence and Complacency. Qualitative research done in the country indicated some healthcare personnel did not know how they could meet parents’ specific questions and concerns. The intervention included educational materials for healthcare personnel to support an open dialogue with parents ahead of vaccination, based on a 5-step “motivational interviewing” approach.
- Another intervention example addressed Complacency and Constraints to vaccination against COVID-19 amongst marginalised groups living in rural areas. Barriers to vaccination against COVID-19 identified amongst marginalised groups in rural areas, including low awareness of the benefits of vaccination and spread of misinformation. With local representatives as vaccination ambassadors, the campaign included targeted information, mobile vaccination teams, extra vaccination days at hospitals and a telephone booking line in multiple languages.
Read more: ECDC’s collated resources on promoting vaccination acceptance and uptake.