Evidence for increased breakthrough rates of SARS-CoV-2 variants of concern in BNT162b2 mRNA vaccinated individuals

The BNT162b2 mRNA vaccine is highly effective against SARS-CoV-2. However,apprehension exists that variants of concerns (VOCs) may surmount vaccine protection,following evidence showing reduced neutralization of VOCs B.1.1.7 and B.1.351 inlaboratory assays. We performed a matched cohort study to examine the distribution ofVOCs in infections of vaccinees, and hypothesized that if vaccine effectiveness against a VOCis reduced, its proportion among breakthrough cases would be higher than in unvaccinatedcontrols. We showed that vaccinees who tested positive at least a week after the seconddose, were disproportionally infected with B.1.351, compared with controls. Those whotested positive between two weeks after the first dose and a week after the second dose,were disproportionally infected by B.1.1.7, suggesting reduced vaccine effectiveness againstboth VOCs at particular time windows. Our results emphasize the importance of rigorouslytracking viral variants, and of increasing vaccination to prevent the spread of VOCs.

BNT162b2 信使核糖核酸（mRNA）疫苗对严重急性呼吸综合征冠状病毒2型（SARS-CoV-2）具有极高的防护效力。然而，学界存在担忧：新冠病毒关切变异株（Variants of Concern，VOCs）或可突破疫苗防护屏障——已有实验室检测证据显示，B.1.1.7与B.1.351这两种变异株的中和活性出现下降。我们开展了一项匹配队列研究，以探究疫苗接种者感染病例中关切变异株的分布情况，并提出假说：若某一关切变异株的疫苗保护效力出现衰减，则该变异株在突破感染病例中的占比将高于未接种疫苗的对照组。研究结果显示，在完成第二剂疫苗接种至少一周后新冠病毒检测呈阳性的疫苗接种者，其感染B.1.351的比例显著高于对照组；而在完成第一剂疫苗接种后两周至第二剂接种后一周期间新冠检测呈阳性的疫苗接种者，则更易感染B.1.1.7，这表明在特定时间窗口内，疫苗对这两种关切变异株的保护效力均有所降低。本研究结果凸显了对病毒变异株进行严格监测、以及提升疫苗接种率以遏制关切变异株传播的重要性。