Efficacy and Safety of COVID-19 Vaccines in Phase III Trials: A Meta-Analysis

Haoyue Cheng; Zhicheng Peng; Wenliang Luo; Shuting Si; Minjia Mo; Haibo Zhou; Xing Xin; Hui Liu; Yunxian Yu

doi:10.3390/vaccines9060582

Efficacy and Safety of COVID-19 Vaccines in Phase III Trials: A Meta-Analysis

Vaccines (Basel). 2021 Jun 1;9(6):582. doi: 10.3390/vaccines9060582.

Authors

Haoyue Cheng^{1

2}, Zhicheng Peng^{1

2}, Wenliang Luo^{1

2}, Shuting Si^{1

2}, Minjia Mo^{1

2}, Haibo Zhou^{1

2}, Xing Xin^{1

2}, Hui Liu³, Yunxian Yu^{1

2}

Affiliations

¹ Department of Public Health and Department of Anesthesiology, The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou 310009, China.
² Department of Epidemiology & Health Statistics, School of Public Health, School of Medicine, Zhejiang University, Hangzhou 310058, China.
³ Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou 310016, China.

Abstract

Nowadays, the vaccination with COVID-19 vaccines is being promoted worldwide, professionals and common people are very concerned about the efficacy and safety of COVID-19 vaccines. No published systematic review and meta-analysis has assessed the efficacy and safety of the COVID-19 vaccines based on data from phase III clinical trials. Therefore, this study has estimated the efficacy and safety of COVID-19 vaccines and the differences between vaccine types. PubMed, Embase, the Cochrane Library, CNKI, Wanfang, medRxiv databases and two websites were used to retrieve the studies. Random-effects models were used to estimate the pooled efficacy and safety with risk ratio (RR). A total of eight studies, seven COVID-19 vaccines and 158,204 subjects were included in the meta-analysis. All the vaccines had a good preventive effect on COVID-19 (RR = 0.17, 95% CI: 0.09-0.32), and the mRNA vaccine (RR = 0.05, 95% CI: 0.03-0.09) was the most effective against COVID-19, while the inactivated vaccine (RR = 0.32, 95% CI: 0.19-0.54) was the least. In terms of safety, the risk of overall adverse events showed an increase in the vaccine group after the first (RR = 1.46, 95% CI: 1.03-2.05) or second (RR = 1.52, 95% CI: 1.04-2.20) injection. However, compared with the first injection, the risk of local (RR = 2.64, 95% CI: 1.02-6.83 vs. RR = 2.25, 95% CI: 0.52-9.75) and systemic (RR = 1.33, 95% CI: 1.21-1.46 vs. RR = 1.59, 95% CI: 0.84-3.01) adverse events decreased after the second injection. As for the mRNA vaccine, the risk of overall adverse events increased significantly, compared with the placebo, no matter whether it was the first (RR = 1.83, 95% CI = 1.80-1.86) or the second (RR = 2.16, 95% CI = 2.11-2.20) injection. All the COVID-19 vaccines that have published the data of phase III clinical trials have excellent efficacy, and the risk of adverse events is acceptable. The mRNA vaccines were the most effective against COVID-19, meanwhile the risk and grade of adverse events was minimal, compared to that of severe symptoms induced by COVID-19.

Keywords: COVID-19; efficacy; meta-analysis; safety; vaccine.

Abstract

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