Data_Sheet_1_Risk assessment and antibody responses to SARS-CoV-2 in healthcare workers.pdf

BackgroundPreventing infection in healthcare workers (HCWs) is crucial for protecting healthcare systems during the COVID-19 pandemic. Here, we investigated the seroepidemiology of SARS-CoV-2 in HCWs in Norway with low-transmission settings.
MethodsFrom March 2020, we recruited HCWs at four medical centres. We determined infection by SARS-CoV-2 RT-PCR and serological testing and evaluated the association between infection and exposure variables, comparing our findings with global data in a meta-analysis. Anti-spike IgG antibodies were measured after infection and/or vaccination in a longitudinal cohort until June 2021.
ResultsWe identified a prevalence of 10.5% (95% confidence interval, CI: 8.8–12.3) in 2020 and an incidence rate of 15.0 cases per 100 person-years (95% CI: 12.5–17.8) among 1,214 HCWs with 848 person-years of follow-up time. Following infection, HCWs (n = 63) mounted durable anti-spike IgG antibodies with a half-life of 4.3 months since their seropositivity. HCWs infected with SARS-CoV-2 in 2020 (n = 46) had higher anti-spike IgG titres than naive HCWs (n = 186) throughout the 5 months after vaccination with BNT162b2 and/or ChAdOx1-S COVID-19 vaccines in 2021. In a meta-analysis including 20 studies, the odds ratio (OR) for SARS-CoV-2 seropositivity was significantly higher with household contact (OR 12.6; 95% CI: 4.5–35.1) and occupational exposure (OR 2.2; 95% CI: 1.4–3.2).
ConclusionWe found high and modest risks of SARS-CoV-2 infection with household and occupational exposure, respectively, in HCWs, suggesting the need to strengthen infection prevention strategies within households and medical centres. Infection generated long-lasting antibodies in most HCWs; therefore, we support delaying COVID-19 vaccination in primed HCWs, prioritising the non-infected high-risk HCWs amid vaccine shortage.

背景 在新型冠状病毒肺炎（COVID-19）大流行期间，保护医护人员（Healthcare Workers, HCWs）免受感染，对维持医疗系统正常运转至关重要。本研究针对低传播环境下挪威的医护人员，开展了严重急性呼吸综合征冠状病毒2（SARS-CoV-2）的血清流行病学调查。
方法 自2020年3月起，我们在四家医疗中心招募医护人员。通过严重急性呼吸综合征冠状病毒2（SARS-CoV-2）逆转录聚合酶链反应（Reverse Transcription-Polymerase Chain Reaction, RT-PCR）检测与血清学检测判定感染状态，评估感染与各类暴露变量间的关联，并通过荟萃分析（meta-analysis）将本研究结果与全球相关数据进行对比。本纵向队列研究于2021年6月前，对感染和/或接种疫苗后的受试者的抗刺突蛋白IgG抗体水平进行了动态检测。
结果 在1214名医护人员、总计848人年的随访中，我们发现2020年的感染患病率为10.5%（95%置信区间（Confidence Interval, CI）：8.8~12.3），发病率为每100人年15.0例（95%CI：12.5~17.8）。感染后，63名医护人员体内产生了持久的抗刺突蛋白IgG抗体，自血清阳性（seropositivity）之日起的半衰期为4.3个月。2020年感染过SARS-CoV-2的46名医护人员，在2021年接种BNT162b2和/或ChAdOx1-S新冠疫苗后的5个月内，其抗刺突蛋白IgG抗体滴度均高于186名未感染过的医护人员。在纳入20项研究的荟萃分析中，存在家庭接触史（比值比（Odds Ratio, OR）=12.6；95%CI：4.5~35.1）与职业暴露史（OR=2.2；95%CI：1.4~3.2）的受试者，SARS-CoV-2血清阳性的比值比均显著升高。
结论 本研究发现，医护人员因家庭接触与职业暴露感染SARS-CoV-2分别存在高风险与中等风险，提示需加强家庭与医疗中心内的感染防控策略。多数医护人员在感染后可产生持久抗体，因此在疫苗短缺的背景下，我们支持对曾感染过新冠病毒的医护人员暂缓接种新冠疫苗，优先为未感染的高风险医护人员接种。