Assessing the Effectiveness of COVID-19/SARS-CoV-2 Vaccinations in Terms of Mortality Rates

COVID-19 is an infectious respiratory disease caused by the SARS-CoV-2 virus. Factors such as cardiorespiratory diseases, age, cancer, and diabetes can influence the virus's lethality. In advanced stages, the virus can lead to permanent damage, complications, or even death. Various vaccines have been developed with claims of reducing cases and mortality rates, leading some countries to mandate vaccination. This paper aims to assess the effectiveness of enforcing vaccination measures in combating the pandemic using statistical methods and regression models. Our statistical analysis reveals a significant difference between 2021 and 2022 in terms of deaths per cases. Additionally, multiple machine learning algorithms, including linear regression, bagging regressor, decision tree regressor, random forest regressor, K-neighbors regressor, and XGBoost regressor, have been employed to predict an approximate 81% decrease in deaths per cases when comparing the early stages of the pandemic to June 10, 2022, concerning the number of vaccinated individuals. These findings provide compelling evidence that vaccinations are effective in the battle against the COVID-19 pandemic.