Behavioral changes associated to the COVID-19 vaccination: evidence from a cross-national online survey

De Gaetano, A., Bajardi, P., Gozzi, N., Perra, N., Perrotta, D., Paolotti, D.
JMIR preprints 47563
26 pages.
submitted on: 24 March 2023 (2023), unpublished
Open Access


Background: During the initial phases of the vaccination campaign worldwide, Non-Pharmaceutical Interventions (NPIs) remained pivotal in the fight against the COVID-19 pandemic. In this context, it is important to understand how the arrival of vaccines affected the adoption of NPIs. Indeed, some individuals might have seen the start of mass vaccination campaigns as the end of the emergency and, as a result, have relaxed their COVID-safe behaviors, facilitating the spread of the virus in a delicate epidemic phase such as the initial rollout.
Objective: Our study aims to collect information about the possible relaxation of behaviors following key events of the vaccination campaign in four countries and to analyse possible associations of these behavioral tendencies with socio-demographic characteristics of participants.
Methods: We developed an online survey named “COVID-19 Prevention and Behavior Survey” that we conducted between November 26 and December 22, 2021. Participants were recruited using targeted ads on Facebook in four different countries: Italy, the United Kingdom, Brazil and South Africa. We measured the onset of relaxation of protective measures in response to key events of the vaccination campaign, namely personal vaccination and vaccination of the most vulnerable population. Through odds ratios and regression analysis we assessed the strength of association between compliance with NPIs and socio-demographic characteristics of participants.
Results: We received 2263 questionnaires from the four countries. Participants reported the most significant changes in social activities, such as going to restaurant or cinema and visiting relatives and friends. This is in good agreement with validated psychological models of health-related behavioral change such as the Health Belief Model (HBM), according to which activities with higher costs and perceived barriers (e.g., the social activities) are more prone to early relaxation. Multivariate analysis using a Generalised Linear Model showed that the two main determinants of the drop of social NPIs are i) having previously tested positive for COVID-19 (after second dose: OR 2.46, 95% CI 1.73-3.49) and ii) living with people at risk (after second dose: OR 1.57, 95% CI 1.22-2.03).
Conclusions: This work shows that particular caution has to be taken during vaccination campaigns. Indeed, people might relax their safe behaviors regardless the dynamics of the epidemic. For this reason, it is crucial to keep high the compliance with NPIs to avoid hindering the beneficial effects of the vaccine. Clinical Trial: Ethical approval: Ethical approval was obtained from the bioethical committee of the University of Turin (Prot. n. 280342 del 8.5.2021).

Keywords: Brazil, Italy, South Africa, United Kingdom
The Max Planck Institute for Demographic Research (MPIDR) in Rostock is one of the leading demographic research centers in the world. It's part of the Max Planck Society, the internationally renowned German research society.