Investigating the impact of the inequalities between countries on COVID-19 vaccination

Abstract

While the introduction of various vaccines is an important step in the fight against the COVID-19 pandemic, the current situation has brought about vaccine inequality worldwide. In our study, we aimed to examine vaccine inequalities among countries and examined the relationship between four indices on human development levels and inequality with the vaccination percentages of countries obtained from the World Health Organization database, which is a publicly available data source. These indices are: Human Development Index (HDI), Inequality Adjusted Human Development Index (IHDI), Commitment to Reduce Inequality Index (CRI), Gini coefficient. According to the COVID-19 vaccination data of the countries, the percentage of full dose vaccination was 25.6% on average in the Low HDI group, 47.8% in the Medium HDI group, 53.2% in the High HDI group and 72.4% in the Very High HDI group, and the difference between the groups was statistically significant (p<0.001).  When the correlations between inequality indices and COVID-19 vaccination were analyzed, a significant (p<0.001), strong and positive correlation (rho:0.64) was found between the Human Development Index (HDI) and the percentage of full vaccination. Similarly, a significant (p<0.001), strong and positive correlation (rho:0.61) was found between the Inequality Adjusted Human Development Index (IHDI) and the percentage of full immunization. A significant (p<0.001), strong and positive correlation (rho:0.56) was found between another inequality index, the Commitment to Reduce Inequality Index (CRI), and the percentage of full immunization.   There is a significant (p=0.026), weak and negative correlation (rho:-0.17) between the Gini Index (GE) and the percentage of full immunization. The results of our study show that as countries' human development levels and commitments to reduce inequality increase, the percentage of the population vaccinated increases.