Khoo Teck Puat National University Children's Medical Institute, National University Health System, Singapore.
Singapore Institute for Clinical Sciences, Agency for Science, Technology and Research Singapore, Singapore; Department of Paediatrics, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.
J Allergy Clin Immunol Pract. 2020 Nov-Dec;8(10):3251-3258. doi: 10.1016/j.jaip.2020.08.026. Epub 2020 Aug 27.
There is a striking age-related disparity in the prevalence and severity of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-induced coronavirus disease 2019 infections, which might be explained by age-dependent immunological mechanisms. These include age-related physiological differences in immunological responses, cross-neutralizing antibodies, and differences in levels and binding affinity of angiotensin-converting enzyme 2, the SARS-CoV-2 target receptor; antibody-dependent enhancement in adults manifesting with an overexuberant systemic inflammation in response to infection; and the increased likelihood of comorbidities in adults and the elderly. Emerging immunological phenomena such as Pediatric Multi-System Inflammatory Disorder Temporally associated with SARS-CoV-2 or Multisystem Inflammatory Syndrome in Children are now being observed, though the underlying mechanisms are still unclear. Understanding the mechanisms through which pediatric patients are protected from severe novel coronaviruses infections will provide critical clues to the pathophysiology of coronavirus disease 2019 infection and inform future therapeutic and prophylactic interventions. Asymptomatic carriage in children may have major public health implications, which will have an impact on social and health care policies on screening and isolation practices, school reopening, and safe distancing requirements in the community.
严重急性呼吸综合征冠状病毒 2(SARS-CoV-2)引起的 2019 年冠状病毒病(COVID-19)感染的流行率和严重程度存在显著的年龄相关差异,这可以用依赖于年龄的免疫机制来解释。这些机制包括免疫反应、中和抗体的年龄相关性生理差异,以及血管紧张素转换酶 2(SARS-CoV-2 的靶受体)水平和结合亲和力的差异;成年人感染后会出现抗体依赖性增强,表现为过度的全身炎症反应;以及成年人和老年人更易发生合并症。目前正在观察到一些新的免疫现象,如与 SARS-CoV-2 相关的儿童多系统炎症障碍或儿童多系统炎症综合征,但潜在机制尚不清楚。了解儿童患者如何免受新型冠状病毒严重感染的机制,将为 COVID-19 感染的病理生理学提供关键线索,并为未来的治疗和预防干预提供信息。儿童无症状携带可能具有重大公共卫生意义,这将对筛查和隔离实践、学校重新开放以及社区安全距离要求等社会和医疗保健政策产生影响。