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Review
. 2022 Jan:114:252-260.
doi: 10.1016/j.ijid.2021.11.009. Epub 2021 Nov 17.

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

Caifang Zheng  1 , Weihao Shao  1 , Xiaorui Chen  1 , Bowen Zhang  1 , Gaili Wang  1 , Weidong Zhang  2
Affiliations
Review

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

Caifang Zheng et al. Int J Infect Dis. 2022 Jan.

Abstract

Objective: To estimate the coronavirus disease 2019 (COVID-19) vaccine effectiveness (VE) against concerned outcomes in real-world settings.

Methods: Studies reporting COVID-19 VE from August 6, 2020 to October 6, 2021 were included. The summary VE (with 95% confidence intervals (95% CI)) against disease related to COVID-19 was estimated. The results were presented in forest plots. Predefined subgroup analyses and sensitivity analyses were also performed.

Results: A total of 51 records were included in this meta-analysis. In fully vaccinated populations, the VE against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, COVID-19-related hospitalization, admission to the intensive care unit, and death was 89.1% (95% CI 85.6-92.6%), 97.2% (95% CI 96.1-98.3%), 97.4% (95% CI 96.0-98.8%), and 99.0% (95% CI 98.5-99.6%), respectively. The VE against infection in the general population aged ≥16 years, the elderly, and healthcare workers was 86.1% (95% CI 77.8-94.4%), 83.8% (95% CI 77.1-90.6%), and 95.3% (95% CI 92.0-98.6%), respectively. For those fully vaccinated against infection, the observed effectiveness of the Pfizer-BioNTech vaccine was 91.2% and of the Moderna vaccine was 98.1%, while the effectiveness of the CoronaVac vaccine was found to be 65.7%.

Conclusions: The COVID-19 vaccines are highly protective against SARS-CoV-2-related diseases in real-world settings.

Keywords: COVID-19; Effectiveness; Real-world; SARS-CoV-2; Vaccine.

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Figures

Figure 1
Figure 1
Results of the literature review according to the inclusion criteria. Flow diagram of the study selection for meta-analysis. Fifty publications and one record reporting COVID-19 vaccine effectiveness in 14 countries from August 6, 2020 to October 6, 2021 were included in the meta-analysis.
Figure 2
Figure 2
COVID-19 vaccine effectiveness (VE) for the prevention of SARS-CoV-2 infection in those with a fully vaccinated status. Forest plot showing VE for the prevention of SARS-CoV-2 infection for fully vaccinated populations; a total of 35 studies contributed information on the effectiveness against SARS-CoV-2 infection.
Figure 3
Figure 3
COVID-19 vaccine effectiveness (VE) for the prevention of COVID-19-related hospitalization, admission to the ICU/severe or critical hospitalization, and death in those with a fully vaccinated status. Forest plot showing VE for the prevention of COVID-19-related hospitalization, severe disease, and death for fully vaccinated populations; a total of 15 included studies contributed information on effectiveness against COVID-19-related hospitalization, four on effectiveness against COVID-19-related severe disease, and eight on effectiveness against COVID-19-related death.
Figure 4
Figure 4
COVID-19 vaccine effectiveness (VE) for the prevention of SARS-CoV-2 infection in different populations. Forest plot showing VE for the prevention of SARS-CoV-2 infection for fully vaccinated populations based on different population groups; a total of 17 included studies contributed information on effectiveness against SARS-CoV-2 infection for healthcare workers (HCWs), 15 on effectiveness against SARS-CoV-2 infection for the elderly, and 11 on effectiveness against SARS-CoV-2 infection for the general population aged ≥16 years.
Figure 5
Figure 5
Summary vaccine effectiveness (VE) against SARS-CoV-2 infection for the different brands in those with a full vaccination status. Forest plot showing VE for the prevention of SARS-CoV-2 infection for fully vaccinated populations with different vaccine brands; a total of 23 included studies contributed information on the effectiveness of the Pfizer-BioNTech vaccine, five on the effectiveness of the Moderna vaccine, and three on the effectiveness of the CoronaVac vaccine.
Figure 6
Figure 6
Summary vaccine effectiveness (VE) against COVID-19-related hospitalization and death of the Pfizer-BioNTech vaccine among fully vaccinated individuals. Forest plot showing VE for the prevention of COVID-19-related hospitalization and death for the Pfizer-BioNTech vaccine among fully vaccinated individuals; a total of nine included studies contributed information on effectiveness against COVID-19-related hospitalization and three on effectiveness against COVID-19-related death for the Pfizer-BioNTech vaccine.
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