Background Data on pediatric coronavirus disease 2019 (COVID-19) has lagged behind adults throughout the pandemic. An understanding of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) viral dynamics in children would enable data-driven public health guidance. Methods Respiratory swabs were collected from children with COVID-19. Viral load was quantified by reverse-transcription polymerase chain reaction (RT-PCR); viral culture was assessed by direct observation of cytopathic effects and semiquantitative viral titers. Correlations with age, symptom duration, and disease severity were analyzed. SARS-CoV-2 whole genome sequences were compared with contemporaneous sequences. Results One hundred ten children with COVID-19 (median age, 10 years [range, 2 weeks–21 years]) were included in this study. Age did not impact SARS-CoV-2 viral load. Children were most infectious within the first 5 days of illness, and severe disease did not correlate with increased viral loads. Pediatric SARS-CoV-2 sequences were representative of those in the community and novel variants were identified. Conclusions Symptomatic and asymptomatic children can carry high quantities of live, replicating SARS-CoV-2, creating a potential reservoir for transmission and evolution of genetic variants. As guidance around social distancing and masking evolves following vaccine uptake in older populations, a clear understanding of SARS-CoV-2 infection dynamics in children is critical for rational development of public health policies and vaccination strategies to mitigate the impact of COVID-19.

中文翻译：

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儿童严重急性呼吸综合征冠状病毒2型感染的病毒学特征

在整个大流行期间，关于 2019 年儿科冠状病毒病 (COVID-19) 的背景数据一直落后于成年人。了解儿童严重急性呼吸系统综合症冠状病毒 2 (SARS-CoV-2) 病毒动力学将使数据驱动的公共卫生指导成为可能。方法 从 COVID-19 患儿身上采集呼吸道拭子。通过逆转录聚合酶链式反应（RT-PCR）量化病毒载量；通过直接观察细胞病变效应和半定量病毒滴度来评估病毒培养物。分析了与年龄、症状持续时间和疾病严重程度的相关性。将 SARS-CoV-2 全基因组序列与同期序列进行了比较。结果 110 名 COVID-19 患儿（中位年龄，10 岁 [范围，2 周至 21 岁]）被纳入本研究。年龄不影响 SARS-CoV-2 病毒载量。儿童在患病的前 5 天内最具传染性，严重疾病与病毒载量增加无关。儿科 SARS-CoV-2 序列代表了社区中的序列，并鉴定了新的变体。结论 有症状和无症状的儿童可以携带大量活的、复制的 SARS-CoV-2，为遗传变异的传播和进化创造了潜在的储存库。随着老年人接种疫苗后有关社交距离和掩蔽的指导不断发展，对儿童 SARS-CoV-2 感染动态的清晰了解对于合理制定公共卫生政策和疫苗接种策略以减轻 COVID-19 的影响至关重要。严重疾病与病毒载量增加无关。儿科 SARS-CoV-2 序列代表了社区中的序列，并鉴定了新的变体。结论 有症状和无症状的儿童可以携带大量活的、复制的 SARS-CoV-2，为遗传变异的传播和进化创造了潜在的储存库。随着老年人接种疫苗后有关社交距离和掩蔽的指导不断发展，对儿童 SARS-CoV-2 感染动态的清晰了解对于合理制定公共卫生政策和疫苗接种策略以减轻 COVID-19 的影响至关重要。严重疾病与病毒载量增加无关。儿科 SARS-CoV-2 序列代表了社区中的序列，并鉴定了新的变体。结论 有症状和无症状的儿童可以携带大量活的、复制的 SARS-CoV-2，为遗传变异的传播和进化创造了潜在的储存库。随着老年人接种疫苗后有关社交距离和掩蔽的指导不断发展，对儿童 SARS-CoV-2 感染动态的清晰了解对于合理制定公共卫生政策和疫苗接种策略以减轻 COVID-19 的影响至关重要。结论 有症状和无症状的儿童可以携带大量活的、复制的 SARS-CoV-2，为遗传变异的传播和进化创造了潜在的储存库。随着老年人接种疫苗后有关社交距离和掩蔽的指导不断发展，对儿童 SARS-CoV-2 感染动态的清晰了解对于合理制定公共卫生政策和疫苗接种策略以减轻 COVID-19 的影响至关重要。结论 有症状和无症状的儿童可以携带大量活的、复制的 SARS-CoV-2，为遗传变异的传播和进化创造了潜在的储存库。随着老年人接种疫苗后有关社交距离和掩蔽的指导不断发展，对儿童 SARS-CoV-2 感染动态的清晰了解对于合理制定公共卫生政策和疫苗接种策略以减轻 COVID-19 的影响至关重要。