Abstract
This study investigates that how the number of COVID-19 vaccines secured correlates with the vaccination coverage (full and booster) depending on whether or not there is trust in national government across 47 countries. The data are based on global figures as of Nov. 2021 and Feb. 2022 while measures for confidence in government is according to Gallup World Poll, Oct. 2021. The model includes an interaction term of these two predictors, also controls for a range of socio-economic factors and country specific variables. The results indicate a non-linear and mixed relationship between the numbers secured, the public trust, and the vaccination rate. In Feb. 2022, with confidence in government, securing number of vaccines to cover 200% of the population (or more) increased the full vaccination rate by 12.26% (95% CI: 11.70-12.81); where number secured was 300% (or more), the coverage increased by 7.46% (95% CI: 6.95-7.97). Under similar scenarios, rate of booster shots increased by 13.16% (95% CI: 12.62-13.70; p < 0.01) and 14.36% (95% CI: 13.86-14.85; p < 0.01), respectively. Where the number secured fell below 200%, confidence in government had a revers relationship with the rate of full vaccination (-2.65; 95% CI: -3.32 to -1.99), yet positive with the rate of booster shots (1.65; 95% CI: 1.18-2.12). These results indicate that better success can be achieved by a combination of factors including securing sufficient number of vaccines as well as improving the public trust. Vaccine abundance, however, cannot be translated into greater success in vaccination coverage. This study highlights the importance of efficiency in acquiring vaccine resources and need for improvement in public belief in immunization programmes rather than stock piling.