Real-world effectiveness of COVID-19 vaccines: a literature review and meta-analysis.

Abstract Objectives To estimate the COVID-19 vaccine effectiveness (VE) against concerned outcomes in real-world settings. Methods We included studies reported the COVID-19 VE from August 6, 2020, to October 6, 2021. We estimated the summary VE with 95% confidence intervals (95% CIs) against disease related to COVID-19. The results were presented in forest plots. Predefined subgroup analysis and sensitivity analysis was also performed. Results 51 records were included in this meta-analysis. In the full vaccination, the VE against SARS-CoV-2 infection, COVID-19 related hospitalization, admission to ICU, and death were 89.1% (95% CI, 85.6 to 92.6), 97.2% (95% CI, 96.1 to 98.3), 97.4% (95% CI, 96.0 to 98.8) and 99.0% (95% CI, 98.5 to 99.6), respectively. It showed that the VE against infection for general population aged 16 years or older, the elderly and health care workers (HCWs) were 86.1% (95% CI, 77.8 to 94.4), 83.8% (95% CI, 77.1 to 90.6) and 95.3% (95% CI, 92.0 to 98.6), respectively. For full vaccination against infection, 91.2% effectiveness of the Pfizer-BioNTech vaccine and the 98.1% effectiveness of Moderna vaccine were observed, while 65.7% effectiveness of the CoronaVac were reported. Conclusions The COVID-19 vaccines are highly protective against SARS-CoV-2 related diseases in the real-world settings.