Abstract
Many governments were forced to implement penalties and mandates to incentivize Covid-19 vaccine uptake and ensure a safe level of vaccination coverage to return to business as usual and lift societal restrictions. Nowadays, most countries around the world have lifted any form of restrictions or mandates. The absence of mandates and penalties might partially explain the significantly lower levels of booster uptake compared to the initial vaccination cycle that is observable globally. Previous literature has underlined the importance of the vaccine characteristics on the uptake, particularly the effectiveness of the vaccines, the risk of side effects and the possible duration of the protection. Little evidence is available on the relative role that social restrictions and mandates play in vaccination decisions. This paper aims at investigating the relative importance that vaccine characteristics versus the intensity of social restrictions and mandates (i.e. lockdown and vaccination mandate to return to work) have on the public vaccination uptake.
A standardized stated choice (SC) survey was administered across 21 countries from 6 continents to provide evidence on: (1) preferences and trade-offs between different vaccine characteristics versus social restrictions; (2) predicted uptake of vaccination against Covid-19; (3) explore vaccine refusal and hesitancy within and across countries. Respondents were asked to indicate their preferred vaccination program between two options and then to indicate whether they would take the vaccines. A total of 7 attributes were included in each option: 5 related to the vaccine characteristics (effectiveness in reducing severe symptoms, risk of severe side effects, duration of the protection, time between the first clinical trial to the market approval and the origin of the manufacturer); 2 related to the policy restrictions (stringency of the social restrictions for leisure activities and the vaccination mandate to return to informal or informal work activities). Respondents were recruited through a specialized market research company from July to December 2022. Our final sample size will be composed of 51,000 respondents and will be representative of the age, gender and geographical location distribution of the general population in each country. Data will be analyzed through advanced discrete choice models (e.g., hybrid choice models) that will allow the exploration of preference heterogeneity across countries and different subgroups of the population based on age, gender, education, religion, and political orientation.
Preliminary analysis from 15 countries reveals that public uptake of COVID-19 vaccination was primarily influenced by the risk of developing severe side effects (b = − 3.552, 95% CI = − 3.616, – 3.489), vaccine effectiveness (b = 1.262, 95% CI = 1.235, 1.289) and the level of social activity restrictions (b = -0.372, 95% CI = -0.383, -0.361). Significant heterogeneity is found across sub-groups of the population by age, income and education levels.
Vaccine characteristics appear to be relatively more important than the level of social restrictions in place for the public. Therefore, consideration of which vaccines to offer may be an effective strategy for policymakers to design vaccination campaigns and increase vaccine uptake.