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Aleksandra Lazić


Iris Žeželj      

The opportunities and the pitfalls of communicating vaccination rates to the public

Aleksandra Lazić, PhD Student, Research Assistant, University of Belgrade

Iris Žeželj, Associate Professor, University of Belgrade

The majority of people worldwide decide to get themselves or their children vaccinated against vaccine-preventable diseases (WHO, 2018). In the ongoing pandemic, the polls have shown that the majority of people in many countries support COVID-19 vaccination (YouGov, 2021). So, why does the media often report about people who refuse vaccination? For example, one recent article asks why Serbia, a COVID-19 “vaccination champion,” has “so many anti-vaxxers” (Vojnović, 2021). Our research (Lazić, & Žeželj) has shown that around 70% of the vaccination rates mentioned in the news articles during the 2017 measles outbreak in Serbia were negatively framed. This means that the rates were often prefaced with words such as “low,” “poor,” or “declining,” even when the majority of individuals have in fact received the vaccine.

A high vaccination rate might tempt people to “free-ride” on collective immunity provided by others and refuse vaccination (e.g., Betsch et al., 2017). With more people getting vaccinated, the risk of infection is lowered, which provides an incentive for individuals to become free-riders who benefit from the vaccination of others while avoiding the cost of vaccination themselves (e.g., money, time, adverse events; Fine et al., 2011). Therefore, according to the selfish-rational model, public messaging should focus on those who refuse vaccination and declining trends in vaccination rates. Although such communication strategies might succeed in appealing to fear or urgency, they have the potential to backfire. If someone has the impression that most others in their community are not getting vaccinated, this might undermine their own motivation to get vaccinated (e.g., Romley et al., 2016). This is in line with the descriptive norms model (Cialdini et al., 1990). Because people tend to conform to what most others are doing, this model would further recommend that public messaging should focus on those who accept vaccination and rising trends in vaccination rates (“more and more people are getting vaccinated”).

When it comes to signaling vaccination rates to the public, the two prominent models in psychology obviously offer competing recommendations. It is also obvious that more research is needed before we can provide concrete guidelines to policy makers and media representatives. In the meantime, both low and high vaccination rates should be communicated carefully and with respect to how they can affect people’s willingness to get vaccinated. For example, one good strategy might be to accompany vaccination rates with an explanation of the importance of reaching collective immunity (e.g., Betsch et al., 2017).

To better understand how people respond to learning about high versus low vaccination rates in their country, Aleksandra put together a project titled “The opportunities and the pitfalls of communicating country-level vaccination rates: Experimentally testing the selfish-rationality vs. the social-rationality hypothesis in a sample of Serbian participants,” for which she received SPSSI’s Researchers in the Global South Grant. She plans to run a series of online experiments, under the supervision of Dr. Iris Žeželj, as a part of her PhD thesis at the University of Belgrade. Additionally, the grant will enable her to translate and adapt the 5C scale of vaccine hesitancy (Betsch et al., 2018) for Serbia. The availability of a standardized scale would support tracking public vaccine concerns and the evaluation of interventions aiming to increase vaccine uptake. If you are interested in this project, you may contact Ms. Lazić at or via Twitter @AleLazic.


Betsch, C., Böhm, R., Korn, L., & Holtmann, C. (2017). On the benefits of explaining herd immunity in vaccine advocacy. Nature Human Behaviour, 1(3).

Betsch, C., Schmid, P., Heinemeier, D., Korn, L., Holtmann, C., & Böhm, R. (2018). Beyond confidence: Development of a measure assessing the 5C psychological antecedents of vaccination. PLOS ONE, 13(12), e0208601.

Cialdini, R. B., Reno, R. R., & Kallgren, C. A. (1990). A focus theory of normative conduct: Recycling the concept of norms to reduce littering in public places. Journal of Personality and Social Psychology, 58(6), 1015–1026.

Fine, P., Eames, K., & Heymann, D. L. (2011). “Herd immunity”: A rough guide. Clinical Infectious Diseases, 52(7), 911–916.

Lazić, A., & Žeželj, I. (2021). Vaccination coverage: A content analysis of online news stories. Manuscript in preparation.

Romley, J., Goutam, P., & Sood, N. (2016). National survey indicates that individual vaccination decisions respond positively to community vaccination rates. PLOS ONE, 11(11), e0166858.

Vojnović, I. (2021, March 30). Otkud vakcinaškom šampionu ovoliki antivakseri? [Why does a vaccination champion have so many anti-vaxxers?]. Istinomer.

WHO (World Health Organization). (2018). 2018 assessment report of the Global Vaccine Action Plan: strategic advisory group of experts on immunization.

YouGov. (2021, January 12). COVID-19: Willingness to be vaccinated.


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