Perez Navarro Andrea, Pilkington Victoria, Pepperrell Toby, Mirchandani Manya, Levi Jacob, Hill Andrew
Faculty of Medicine, Imperial College London, London, United Kingdom.
Oxford University Clinical Academic Graduate School, University of Oxford, Oxford, United Kingdom.
Open Forum Infect Dis. 2022 Aug 22;9(9):ofac408. doi: 10.1093/ofid/ofac408. eCollection 2022 Sep.
Five severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccines are approved in North America and/or Europe: Pfizer/BioNTech, Moderna, Janssen, Oxford-AstraZeneca, and Novavax. Other vaccines have been developed, including Sinopharm, SinoVac, QazVac, Covaxin, Soberana, Zifivax, Medicago, Clover, and Cansino, but they are not approved in high-income countries. This meta-analysis compared the efficacy of US Food and Drug Administration (FDA)/European Medicines Agency (EMA)-approved and -unapproved vaccines in randomized clinical trials (RCTs).
A systematic review of trial registries identified RCTs of SARS-CoV-2 vaccines. Risk of bias was assessed using the Cochrane tool (RoB 2). In the meta-analysis, relative risks of symptomatic infection and severe disease were compared for each vaccine versus placebo, using Cochrane-Mantel Haenszel Tests (random effects method).
Twenty-two RCTs were identified and 1 was excluded for high-risk of bias. Ten RCTs evaluated 5 approved vaccines and 11 RCTs evaluated 9 unapproved vaccines. In the meta-analysis, prevention of symptomatic infection was 84% (95% confidence interval [CI], 68%-92%) for approved vaccines versus 72% (95% CI, 66%-77%) for unapproved vaccines, with no significant difference between vaccine types ( = .12). Prevention of severe SARS-CoV-2 infection was 94% (95% CI, 75%-98%) for approved vaccines versus 86% (95% CI, 76%-92%) for unapproved vaccines ( = .33). The risk of serious adverse events was similar between vaccine types ( = .12).
This meta-analysis of 21 RCTs in 390 459 participants showed no significant difference in efficacy between the FDA/EMA-approved and -unapproved vaccines for symptomatic or severe infection. Differences in study design, endpoint definitions, variants, and infection prevalence may have influenced results. New patent-free vaccines could lower costs of worldwide SARS-CoV-2 vaccination campaigns significantly.
五种严重急性呼吸综合征冠状病毒2（SARS-CoV-2）疫苗在北美和/或欧洲获得批准：辉瑞/生物科技、莫德纳、杨森、牛津-阿斯利康和诺瓦瓦克斯。其他疫苗也已研发出来，包括国药集团、科兴生物、哈萨克斯坦QazVac、印度巴拉特生物技术公司的Covaxin、古巴Soberana、津巴布韦Zifivax、加拿大 Medicago、中国三叶草生物和中国康希诺生物，但它们在高收入国家未获批准。这项荟萃分析比较了美国食品药品监督管理局（FDA）/欧洲药品管理局（EMA）批准和未批准的疫苗在随机临床试验（RCT）中的疗效。
方法：对试验注册库进行系统评价，以确定SARS-CoV-2疫苗的随机对照试验。使用Cochrane工具（RoB 2）评估偏倚风险。在荟萃分析中，使用Cochrane-Mantel Haenszel检验（随机效应方法）比较每种疫苗与安慰剂相比出现症状性感染和严重疾病的相对风险。
共确定了22项随机对照试验，其中1项因高偏倚风险被排除。10项随机对照试验评估了5种已批准的疫苗，11项随机对照试验评估了9种未批准的疫苗。在荟萃分析中，已批准疫苗预防症状性感染的有效率为84%（95%置信区间[CI]，68%-92%），未批准疫苗为72%（95%CI，66%-77%），不同类型疫苗之间无显著差异（P = 0.12）。已批准疫苗预防严重SARS-CoV-2感染的有效率为94%（95%CI，75%-98%），未批准疫苗为86%（95%CI，76%-92%）（P = 0.33）。不同类型疫苗之间严重不良事件的风险相似（P = 0.12）。
这项对390459名参与者的21项随机对照试验的荟萃分析表明，FDA/EMA批准和未批准的疫苗在预防症状性或严重感染方面的疗效无显著差异。研究设计、终点定义、病毒变种和感染流行率的差异可能影响了结果。新型无专利疫苗可显著降低全球SARS-CoV-2疫苗接种运动的成本。
