Molecular Virology Unit, Microbiology and Virology Department, Fondazione IRCCS Policlinico San Matteo, Pavia, Italy.
Department of Clinical, Surgical, Diagnostic and Pediatric Sciences, University of Pavia, Pavia, Italy.
Nat Commun. 2021 Oct 15;12(1):6032. doi: 10.1038/s41467-021-26154-6.
Vaccine breakthrough SARS-CoV-2 infection has been monitored in 3720 healthcare workers receiving 2 doses of BNT162b2. SARS-CoV-2 infection is detected in 33 subjects, with a 100-day cumulative incidence of 0.93%. Vaccine protection against acquisition of SARS-CoV-2 infection is 83% (95%CI: 58-93%) in the overall population and 93% (95%CI: 69-99%) in SARS-CoV-2-experienced subjects, when compared with a non-vaccinated control group from the same Institution, in which SARS-CoV-2 infection occurs in 20/346 subjects (100-day cumulative incidence: 5.78%). The infection is symptomatic in 16 (48%) vaccinated subjects vs 17 (85%) controls (p = 0.01). All analyzed patients, in whom the amount of viral RNA was sufficient for genome sequencing, results infected by the alpha variant. Antibody and T-cell responses are not reduced in subjects with breakthrough infection. Evidence of virus transmission, determined by contact tracing, is observed in two (6.1%) cases. This real-world data support the protective effect of BNT162b2 vaccine. A triple antigenic exposure, such as two-dose vaccine schedule in experienced subjects, may confer a higher protection.
在 3720 名接受 2 剂 BNT162b2 疫苗的医护人员中，监测到了疫苗突破 SARS-CoV-2 感染。在 33 名受试者中检测到 SARS-CoV-2 感染，100 天累积发病率为 0.93%。与同一机构未接种疫苗的对照组相比，该疫苗对 SARS-CoV-2 感染的总体保护率为 83%（95%CI：58-93%），对有 SARS-CoV-2 感染史的受试者的保护率为 93%（95%CI：69-99%）。在接种疫苗的 33 名受试者中，有 16 名（48%）出现症状，而对照组中有 17 名（85%）出现症状（p=0.01）。所有分析的患者中，病毒 RNA 量足以进行基因组测序的患者，结果均感染了 alpha 变异株。在发生突破感染的受试者中，抗体和 T 细胞反应并未减弱。通过接触追踪确定了病毒传播的证据，在 2 例（6.1%）中观察到。这些真实世界的数据支持 BNT162b2 疫苗的保护作用。在有经验的受试者中进行三价抗原暴露，如两剂疫苗接种方案，可能会提供更高的保护。
