In a study, researchers found that to combat the growing COVID-19 pandemic. In their study, they evaluated the effectiveness of COVID-19 vaccinations in reducing infections and mortality caused by COVID-19. A database search included 17 randomized clinical trials of COVID-19 vaccines. Based on the number of deaths, hospitalizations, and symptomatic and severe illnesses caused by COVID-19, investigators compared the COVID-19 vaccines. Additionally, they examined COVID-19’s effectiveness across a range of SARS-CoV-2 genotypes and age groups. To pool relative risk (RR), a random effects model utilizing the Mantel-Haenszel approach was utilized. According to their meta-analysis, complete immunization could reduce the incidence of COVID-19-related hospitalization, mortality, and mild or symptomatic symptoms. The COVID-19 vaccinations also worked well against SARS-CoV-2 variations (RR=0.36; 95% CI [0.25; 0.53], P<0.0001). However, immunization effectiveness differed depending on COVID-19 variants. The examination of COVID-19 vaccines in various age groups also revealed that the outcomes were consistent: the risk was marginally lower in adults than in the old cohort (≥65) (RR=0.16, 95% CI [0.11; 0.23]) and (RR=0.19, 95% CI [0.12; 0.30]), respectively. Data from COVID-19 vaccine clinical trials show encouraging results, but more clinical testing is necessary to explore the vaccines’ efficacy properly, especially in light of the emergence of additional SARS-CoV-2 mutations.