Trust and COVID-19 vaccine hesitancy
Carrieri V., Guthmuller S., Wübker A., 2023 – Scientific Reports
The COVID-19 pandemic has brought vaccine hesitancy back into focus. However, this is not a new issue. In many developed countries, a significant number of people are hesitant to get vaccinated against diseases that vaccines can prevent, especially in children, for illnesses like measles and rubella. To be effective, public health policies need to take into account the impact of trust on preventive health decisions and address it accordingly.
In the article “Trust and COVID-19 vaccine hesitancy,” published in Scientific Reports, Vincenzo Carrieri, Sophie Guthmuller, and Ansgar Wübker investigate how the trust in different areas (science, institutions, traditional media, and social media) relates to vaccine hesitancy during the COVID-19 pandemic. The study uses weekly data collected in 2021 across 27 European countries, covering over 35,000 individuals.
The research investigates the determinants of vaccine hesitancy, focusing on the role played by trust in media, institutions and social platforms, as well as by socioeconomic and demographic factors. It also analyses how trust develops in these areas. Finally, it studies the effects of the temporary suspension of the AstraZeneca vaccine in March 2021 on both trust and the interaction between trust and vaccine hesitation. An individual is defined as “vaccine hesitant” if he/she replied “Rather unlikely or very unlikely” to the question: “How likely or unlikely is it that you will take the COVID-19 vaccine when it becomes available to you?”.
Figure 1 shows that trust in science is the strongest factor negatively linked to vaccine hesitancy: a one-point increase in trust reduces hesitancy by 3%. On the other hand, high trust in social media increases hesitancy by about 2%. This effect is even stronger when social media is the main source of information, as it amplifies the spread of misinformation and conspiracy theories.
Figure 2 shows regression coefficients for the main factors influencing trust formation across various dimensions. First, the data points to that the individuals who use social media as their primary source of information exhibit significantly lower trust in the healthcare system, the European Union, the government, news outlets, science, and pharmaceutical companies, compared to those who mainly rely on traditional media (reference group: TV users). Unsurprisingly, they display greater trust in social media. Additionally, the study finds that people living in rural areas, facing significant financial difficulties in meeting daily expenses, showing poor or very poor health, and with lower levels of education, tend to have generally lower trust in public institutions (e.g., science, government, the healthcare system, or the EU).
Furthermore, the detailed analysis of the impact of the temporary suspension of the AstraZeneca vaccine reveals a significant increase in vaccine hesitancy in the week following the event, with a 4-percentage-point rise. Figure 3 highlights how this effect is more pronounced among individuals with low trust in science. Specifically, while the group with high trust in science show no significant changes in their intention to get vaccinated, those with low trust experience a marked increase in hesitancy. The study delves deeper into this effect by also considering the role of individual socio-economic conditions. It finds that people with low trust in science and facing economic difficulties exhibit the most significant rise in vaccine hesitancy immediately after the AstraZeneca suspension.
This research points out the critical role of trust as a key determinant of vaccination decisions. Public policies should focus on strengthening trust in science and institutions, while contrasting the spread of misinformation on social media. Moreover, involving doctors and healthcare professionals as intermediaries in vaccination communication and promotion is crucial. Indeed, vaccination decisions made without the guidance of healthcare professionals’ risk being influenced by inaccurate and often anti-vaccination information channels.
More broadly, the recent debate on vaccine hesitancy underscores how the pandemic has intensified challenges related to misinformation and trust in institutions. Recent developments, such as discussions on the role of artificial intelligence in monitoring misinformation and initiatives to enhance government transparency, offer promising avenues to address vaccine hesitancy and, more generally, to promote pro-social behaviors among individuals.