The COVID-19 pandemic has highlighted the urgent need to address vaccine coverage inequality. Despite calls from scientists and national organizations, progress in ensuring equitable access to vaccines has been slow. This study aims to reveal the COVID-19 vaccine coverage inequality and investigate the predictive effect of attitudes toward science and religion on real-word vaccination uptake. We draw on three high-quality, large-scale databases to unveil real-world vaccine coverage, which stood at an average of 53% of the population by mid-2022. The vaccination rate varies based on a country's income, with higher-income nations having higher vaccination rates and faster vaccination speed. Regression models and a multiverse analysis reveal that both country-level attitudes towards science and religion, as well as religious faith, are linked to vaccination rate at the country level. Countries where a higher proportion of the population prioritize religious beliefs over scientific evidence when the two come into conflict tend to have lower vaccination coverage rates and slower vaccination speeds. These findings suggest that scientists and policymakers must take into account social and cultural characteristics of populations when addressing vaccine inequality.