Department of Biomedical Sciences and Human Oncology-Hygiene Section, University of Bari, Bari, Italy.
Azienda Ospedaliero-Universitaria Consorziale Policlinico di Bari, Bari, Italy.
Clin Microbiol Infect. 2021 Aug;27(8):1174.e1-1174.e4. doi: 10.1016/j.cmi.2021.05.007. Epub 2021 May 10.
In December 2020, Italy began a national immunization campaign using the BNT162b2 coronavirus disease 2019 (COVID-19) mRNA vaccine, prioritizing healthcare workers (HCWs). Immune serum from vaccinated subjects seems (largely) to retain titres of neutralizing antibodies, even against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) VOC 202012/01-lineage B.1.1.7. Here, we describe an outbreak of SARS-CoV-2 lineage B.1.1.7 infection in three HCWs in a hospital setting; two of the HCWs were fully vaccinated (i.e. had received two doses).
Two physicians and one nurse working on the same shift on 20th February 2021 were involved in the outbreak. Real-time PCR, antigen tests, and serological tests for the IgG anti-spike protein of SARS-CoV-2 were performed, along with whole-genome sequencing (WGS).
SARS-CoV-2 infection was confirmed in all three HCWs; all presented with mild symptoms of COVID-19. The two physicians were fully vaccinated with BNT162b2 vaccine, with the second dose administered 1 month before symptom onset. Both had high titres of IgG anti-spike antibodies at the time of diagnosis. WGS confirmed that all virus strains were VOC 202012/01-lineage B.1.1.7, suggesting a common source of exposure. Epidemiological investigation revealed that the suspected source was a SARS-CoV-2-positive patient who required endotracheal intubation due to severe COVID-19. All procedures were carried out using a full suite of personal protective equipment (PPE).
This mini-outbreak highlights some important issues about the efficacy of vaccines against transmission of SARS-CoV-2 variants, the high risk of exposure among HCWs, and the need for optimized implementation of PPE in hospitals. The wide circulation of VOC 202012/01 in Europe and Italy highlights the need to improve surveillance and genetic sequencing.
2020 年 12 月，意大利开始使用 BNT162b2 冠状病毒病 2019（COVID-19）mRNA 疫苗进行全国性免疫接种，优先考虑医疗保健工作者（HCWs）。接种疫苗的受试者的免疫血清似乎（在很大程度上）保留了中和抗体的滴度，即使针对严重急性呼吸综合征冠状病毒 2（SARS-CoV-2）VOC 202012/01 谱系 B.1.1.7。在这里，我们描述了在医院环境中，三名 HCWs 中爆发的 SARS-CoV-2 谱系 B.1.1.7 感染；其中两名 HCWs 已完全接种疫苗（即已接种两剂）。
2021 年 2 月 20 日，同班次的两名医生和一名护士参与了此次暴发。进行了实时 PCR、抗原检测和针对 SARS-CoV-2 刺突蛋白的 IgG 抗体血清学检测，以及全基因组测序（WGS）。
所有三名 HCWs 均确诊为 SARS-CoV-2 感染；均表现为 COVID-19 轻症。两名医生均已完全接种 BNT162b2 疫苗，第二剂疫苗在症状出现前 1 个月接种。两人在诊断时均具有高滴度的 IgG 抗刺突抗体。WGS 证实所有病毒株均为 VOC 202012/01 谱系 B.1.1.7，表明存在共同的暴露源。流行病学调查显示，疑似源是一名因 COVID-19 严重而需要气管插管的 SARS-CoV-2 阳性患者。所有程序均使用全套个人防护设备（PPE）进行。
此次小型暴发突出了疫苗对 SARS-CoV-2 变体传播的功效、HCWs 之间暴露风险高以及医院内优化实施 PPE 的必要性等一些重要问题。VOC 202012/01 在欧洲和意大利的广泛传播凸显了加强监测和基因测序的必要性。
