Statistical Analysis of COVID-19 Vaccine Effectiveness:A Retrospective Study Based on Global Data

The COVID-19 pandemic has led to extensive global vaccination campaigns aimed at reducing infection rates, hospitalizations, and mortality. However, disparities in vaccine distribution and the emergence of new variants have raised concerns about real-world vaccine effectiveness across different populations. This paper evaluates the relationship between vaccination rates and public health outcomes, including infection rates, hospitalization rates, and mortality rates, across 15 countries spanning high-, middle-, and low-income regions. Results indicate a strong negative correlation between vaccination rates and severe COVID-19 outcomes, with mRNA vaccines (Pfizer-BioNTech, Moderna) exhibited superior protection. Additionally, countries with early booster rollouts exhibited 30% lower hospitalization rates than those with delayed booster programs.These findings highlight the critical role of vaccination campaigns, the necessity of booster doses for sustained immunity, and the urgent need for equitable vaccine distribution to mitigate global health disparities.