Objective: To evaluate systematically the efficacy and safety of COVID-19 vaccines.
Methods: PubMed, Embase, Cochrane Library, Clinicaltrial.gov, CNKI, Wanfang Data, China Biomedical Literature Service System, and China Clinical Trial Registry were searched for randomized controlled trials of COVID-19 vaccines published up to December 31, 2020. The Cochrane bias risk assessment tool was used to assess the quality of studies. A qualitative analysis was performed on the results of clinical trials.
Results: Thirteen randomized, blinded, controlled trials, which involved the safety and efficacy of 11 COVID-19 vaccines, were included. In 10 studies, the 28-day seroconversion rate of subjects exceeded 80%. In two 10 000-scale clinical trials, the vaccines were effective in 95% and 70.4% of the subjects, respectively. The seroconversion rate was lower than 60% in only one study. In six studies, the proportion of subjects who had an adverse reaction within 28 days after vaccination was lower than 30%. This proportion was 30%-50% in two studies and > 50% in the other two studies. Most of the adverse reactions were mild to moderate and resolved within 24 hours after vaccination. The most common local adverse reaction was pain or tenderness at the injection site, and the most common systemic adverse reaction was fatigue, fever, or bodily pain. The immune response and incidence of adverse reactions to the vaccines were positively correlated with the dose given to the subjects. The immune response to the vaccines was worse in the elderly than in the younger population. In 6 studies that compared single-dose and double-dose vaccination, 4 studies showed that double-dose vaccination produced a stronger immune response than single-dose vaccination.
Conclusions: Most of the COVID-19 vaccines appear to be effective and safe. Double-dose vaccination is recommended. However, more research is needed to investigate the long-term efficacy and safety of the vaccines and the influence of dose, age, and production process on the protective efficacy.
目的: 系统评价新型冠状病毒肺炎(COVID-19)疫苗的有效性和安全性。
方法: 通过计算机检索有关COVID-19疫苗的临床随机对照试验文献，对临床试验结果进行定性分析。检索时间为各数据库建库至2020年12月31日。所检索的数据库包括PubMed、Embase、Cochrane图书馆、Clinicaltrial.gov、中国知网、万方数据、中国生物医学文献服务系统和中国临床试验注册中心。使用Cochrane偏倚风险评估工具评估文献质量。
结果: 纳入了13项随机、盲法、对照试验，涉及11种COVID-19疫苗接种的安全性和有效性。在其中10项研究中，受试者的28 d血清转化率超过80%；2项万人规模的临床试验中，分别取得了95%和70.4%的有效率；1项研究的血清转化率低于60%。在对接种后28 d内不良反应发生率的分析显示，6项研究不良反应发生率低于30%，2项研究为30%~50%，2项研究高于50%。在13项研究中，疫苗接种不良反应事件绝大部分为轻度到中度，在接种后24 h内缓解；最常见的局部不良反应为注射部位疼痛或压痛，最常见的系统性不良反应为疲劳、发热或躯体痛。受试者对疫苗的免疫反应和不良反应发生率与接种剂量呈正相关。老年人对疫苗的免疫反应较年轻人差。6项研究比较了疫苗单剂量与双剂量接种的效应，其中4项研究显示双剂量接种比单剂量接种产生更强的免疫反应。
结论: 大部分COVID-19疫苗具有较好的有效性和安全性；推荐双剂量接种。然而COVID-19疫苗的长期有效性、安全性及剂量、年龄和工艺差异对保护效力的影响需要更多的研究证实。