Abhilash Kundavaram Paul Prabhakar, Nellimootil Mathew Varghese, Chacko Binila, Hazra Darpanarayan, Coelho Victor, Jesudasan John Emmanuel, Gunasekaran Karthik, Thomas Lovely, Ramchandra More Atul, Melchizedek Jonathan, Gunaraj Henah Meshack, Moorthy Mahesh, Peter John Victor
Department of Emergency Medicine, Christian Medical College Vellore, Vellore 632004, Tamil Nādu, India.
Department of Respiratory Medicine, Christian Medical College Vellore, Vellore 632004, Tamil Nādu, India.
World J Virol. 2025 Jun 25;14(2):99663. doi: 10.5501/wjv.v14.i2.99663.
In the initial stages of the coronavirus disease 2019 (COVID-19) pandemic, healthcare workers (HCWs) who were immunologically naive to COVID-19, were exposed to a highly transmissible virus.
To compare infection risk among HCWs in high-risk (HR) and low-risk (LR) areas.
Data on reverse transcriptase-polymerase chain reaction confirmed clinical infection and samples for nucleocapsid, and spike protein antibodies were collected at five time-points (T1 to T5) from HCWs in the emergency department and intensive care unit (HR group) and pre-clinical and para-clinical areas (LR). For the sero-study, only participants who provided at least one baseline sample and one during the second wave (T4 or T5) were analysed. Since Covishield elicits only spike protein antibodies, subclinical infection was diagnosed if asymptomatic unvaccinated and Covishield vaccinated individuals tested positive for nucleocapsid antibody.
Overall, by T5, clinical infection rate was similar in the HR (120/366, 32.8%) and LR (22/82, 26.8%) groups ( = 0.17). However, before vaccination (T3), more HCWs in the HR group developed COVID-19 infection (21.9% 8.8%, = 0.046). In the sero-study group, clinical infection occurred in 31.5% (45/143) and 23.7% (14/59) in the HR and LR groups respectively ( = 0.23). Spike antibody was detected in 140/143 (97.9%) and 56/59 (94.9%) and nucleocapsid antibody was positive in 95/143 (66.4%) and 35/59 (59.3%) in the HR and LR groups respectively ( = 0.34). Subclinical infection rate (HR 34.9%, LR 35.6%, = 0.37) and hospitalization rate were similar. There was no mortality.
Before vaccination, HCWs in HR areas had a higher risk of infection. Seroprevalence studies suggest that sub-clinical infection was not uncommon.
在2019冠状病毒病（COVID-19）大流行的初始阶段，对COVID-19缺乏免疫的医护人员接触到了一种高度传染性的病毒。
比较高风险（HR）和低风险（LR）地区医护人员的感染风险。
在五个时间点（T1至T5）收集急诊科和重症监护病房（HR组）以及临床前和辅助临床区域（LR）医护人员的逆转录聚合酶链反应确诊的临床感染数据以及核衣壳和刺突蛋白抗体样本。对于血清学研究，仅分析提供了至少一份基线样本和第二波期间（T4或T5）一份样本的参与者。由于Covishield仅引发刺突蛋白抗体，如果无症状的未接种疫苗者和接种Covishield疫苗者的核衣壳抗体检测呈阳性，则诊断为亚临床感染。
总体而言，到T5时，HR组（120/366，32.8%）和LR组（22/82，26.8%）的临床感染率相似（P = 0.17）。然而，在接种疫苗前（T3），HR组中更多的医护人员感染了COVID-19（21.9%对8.8%，P = 0.046）。在血清学研究组中，HR组和LR组的临床感染发生率分别为31.5%（45/143）和23.7%（14/59）（P = 0.23）。HR组和LR组分别有140/143（97.9%）和56/59（94.9%）检测到刺突抗体，95/143（66.4%）和35/59（59.3%）检测到核衣壳抗体呈阳性（P = 0.34）。亚临床感染率（HR 34.9%，LR 35.6%，P = 0.37）和住院率相似。无死亡病例。
在接种疫苗前，HR地区的医护人员感染风险较高。血清流行率研究表明亚临床感染并不罕见。
