■自然获得性免疫对SARS-CoV-2再感染的保护效力仍存在争议。
■系统地评估天然免疫对随后的SARS-CoV-2感染具有不同变体的保护作用。
■我们搜索了2023年3月5日之前在七个数据库中发表的相关研究。分析中包含的合格研究报告了先前有或没有SARS-CoV-2感染的人群的后续感染风险。主要结果是两组之间SARS-CoV-2再感染/感染的总体合并发生率比(IRR)。我们还专注于自然免疫对不同SARS-CoV-2变体的再感染/感染的保护效力。我们使用了随机效应模型来汇集数据,并使用修剪填充方法获得了偏置调整结果。进行Meta回归和亚组分析以探索异质性的来源。通过逐一排除纳入研究进行敏感性分析,以评估结果的稳定性。
■我们确定了40篇符合条件的文章,其中包括超过2000万没有SARS-CoV-2疫苗接种史的人。自然获得的抗体对再感染的偏倚调整功效估计为65%(合并IRR=0.35,95%CI=0.26-0.47),对有症状的COVID-19病例(合并IRR=0.15,95%CI=0.08-0.26)的疗效高于无症状感染(合并IRR=0.40,95%CI=0.29-0.54)。Meta回归显示,SARS-CoV-2变异体是一个有统计学意义的效应调节剂,这解释了内部收益率变化的46.40%。对于不同的SARS-CoV-2变体,Alpha的合并内部收益率(合并内部收益率=0.11,95%CI=0.06-0.19),Delta(合并IRR=0.19,95%CI=0.15-0.24)和Omicron(合并IRR=0.61,95%CI=0.42-0.87)变体越来越高。在其他亚组分析中,SARS-CoV-2感染的合并IRR在不同国家有统计学差异,出版年份和人口的纳入结束时间,差异显著(p=0.02,p<0.010和p<0.010),分别。血清阳性人群中随后感染的风险似乎随着时间的推移而缓慢增加。尽管纳入的研究存在异质性,敏感性分析显示结果稳定。
■以前的SARS-CoV-2感染可防止前omicron再感染,但对omicron的打击较少。持续的病毒突变需要关注和预防策略,比如疫苗追赶,结合多种因素。
UNASSIGNED: The protective effectiveness provided by naturally acquired immunity against SARS-CoV-2
reinfection remain controversial.
UNASSIGNED: To systematically evaluate the protective effect of natural immunity against subsequent SARS-CoV-2 infection with different variants.
UNASSIGNED: We searched for related studies published in seven databases before March 5, 2023. Eligible studies included in the analysis reported the risk of subsequent infection for groups with or without a prior SARS-CoV-2 infection. The primary outcome was the overall pooled incidence rate ratio (IRR) of SARS-CoV-2
reinfection/infection between the two groups. We also focused on the protective effectiveness of natural immunity against
reinfection/infection with different SARS-CoV-2 variants. We used a random-effects model to pool the data, and obtained the bias-adjusted results using the trim-and-fill method. Meta-regression and subgroup analyses were conducted to explore the sources of heterogeneity. Sensitivity analysis was performed by excluding included studies one by one to evaluate the stability of the results.
UNASSIGNED: We identified 40 eligible articles including more than 20 million individuals without the history of SARS-CoV-2 vaccination. The bias-adjusted efficacy of naturally acquired antibodies against
reinfection was estimated at 65% (pooled IRR = 0.35, 95% CI = 0.26-0.47), with higher efficacy against symptomatic COVID-19 cases (pooled IRR = 0.15, 95% CI = 0.08-0.26) than asymptomatic infection (pooled IRR = 0.40, 95% CI = 0.29-0.54). Meta-regression revealed that SARS-CoV-2 variant was a statistically significant effect modifier, which explaining 46.40% of the variation in IRRs. For different SARS-CoV-2 variant, the pooled IRRs for the Alpha (pooled IRR = 0.11, 95% CI = 0.06-0.19), Delta (pooled IRR = 0.19, 95% CI = 0.15-0.24) and Omicron (pooled IRR = 0.61, 95% CI = 0.42-0.87) variant were higher and higher. In other subgroup analyses, the pooled IRRs of SARS-CoV-2 infection were statistically various in different countries, publication year and the inclusion end time of population, with a significant difference (p = 0.02, p < 0.010 and p < 0.010), respectively. The risk of subsequent infection in the seropositive population appeared to increase slowly over time. Despite the heterogeneity in included studies, sensitivity analyses showed stable results.
UNASSIGNED: Previous SARS-CoV-2 infection provides protection against pre-omicron
reinfection, but less against omicron. Ongoing viral mutation requires attention and prevention strategies, such as vaccine catch-up, in conjunction with multiple factors.