key: cord-0050343-qzyxhpdc authors: Yonker, Lael M.; Neilan, Anne M.; Bartsch, Yannic; Patel, Ankit B.; Regan, James; Arya, Puneeta; Gootkind, Elizabeth; Park, Grace; Hardcastle, Margot; St. John, Anita; Appleman, Lori; Chiu, Michelle L.; Fialkowski, Allison; De la Flor, Denis; Lima, Rosiane; Bordt, Evan A.; Yockey, Laura J.; D’Avino, Paolo; Fischinger, Stephanie; Shui, Jessica E.; Lerou, Paul H.; Bonventre, Joseph V.; Yu, Xu G.; Ryan, Edward T.; Bassett, Ingrid V.; Irimia, Daniel; Edlow, Andrea G.; Alter, Galit; Li, Jonathan Z.; Fasano, Alessio title: Reply date: 2020-09-18 journal: J Pediatr DOI: 10.1016/j.jpeds.2020.09.035 sha: dc017ff3fd0fe6290862f240d60e8360068280cd doc_id: 50343 cord_uid: qzyxhpdc nan Our results support published literature that SARS-CoV-2 infected children have mild or no symptoms. 2 In our study, 11 children presented for SARS-CoV-2 testing because of exposure to an infected individual, rather than symptoms. Three (27% of those presenting for exposure alone) were confirmed infected, with a median viral load of 6.3 log 10 RNA copies/mL, which is comparable with the viral load seen in symptomatic children within the first two days of illness. The ages of these children were 8, 16, and 17 years. The number of asymptomatic individuals included in this study was small, primarily because of the limited resources for viral testing at the time of this study (March-June 2020) with clinical guidance recommending quarantine rather than viral testing. However, a case series in Korea of 91 children exposed to adults with COVID-19 found that only 8.5% of these children had symptoms concerning for COVID-19 prior to testing, and 22% of these individuals remained completely asymptomatic for the duration of their infection. 3 We report the viral load in children in the first two days of illness is significantly higher than adults hospitalized within 7-26 days of infection. We did not find that children have higher viral loads than adults in general, although other studies have suggested this finding 6 . When stratified for time, there are no apparent differences between adults and children, although our sample size of adults in our cohort with <7 days of symptoms is small. We report that in children, viral load in the respiratory secretions decreases over time, aligning with reports of decreasing viral load in infected adults over time. 7 We did not report any viremia in our MIS-C cohort, nor do we report MIS-C as a barrier to opening schools. Children generally fare well with acute infection with SARS-CoV-2 but, rarely, can develop the post-infectious, inflammatory illness, MIS-C. 8 The impact of school closures on the mental health and well-being of children is undeniable. We agree that the repercussions of the COVID-19 pandemic are widespread and that economic, social, and mental health implications should not be overlooked. Vulnerable populations are most hard hit by this pandemic, across all ages. Policy makers must find ways to provide services and education in a way that is safe for the community. We agree that indiscriminately closing schools is not necessary and could be harmful to the well-being of a child. Until highly effective therapies or vaccines are universally available, physical barriers (mask-wearing, social distancing, quarantine), frequent hand washing, and/or frequent viral testing are the only measures we have to limit the spread of the disease. Administrators of daycare facilities, elementary schools, high schools, and colleges will have to work with policy makers to continue to provide educational, nutritional and other critical services safely, and adaptations will likely need to change over time to respond to local transmission rates and COVID-19 incidence. Our study did not directly assess person-to-person transmission; therefore, we cannot state whether there is a correlation between viral load and transmission. Earlier transmission studies suggest children play a minimal role in the spread of infection despite children being as likely as J o u r n a l P r e -p r o o f adults to be infected by SARS-CoV-2 11 . In fact, one surveillance study in Switzerland from March through April 2020 reported that a child developed symptoms before any other household contact in 8% of households, but child-child or child-adult transmission could not be confirmed 12 Ultimately, the risk of school-based outbreaks will depend on both the extent and adherence to infection control measures as well as on our collective ability to bring community prevalence to a low level. Safe school re-opening is only one of many factors that are critical to bring community prevalence below target levels. We need widely available SARS-CoV-2 testing and studies focused on understanding and reducing transmission. We need to learn from successes of some communities and identify challenges in others. Ultimately, until we have a vaccine and/or effective antiviral treatments, we must do what we can to mitigate the spread of this pandemic. J o u r n a l P r e -p r o o f Denis De la Flor Massachusetts General Hospital, Department of Pediatrics Massachusetts General Hospital Department of Obstetrics and Gynecology, Division of Maternal-Fetal Medicine Ragon Institute of Massachusetts General Hospital SARS-CoV-2 Infection in Children Clinical Characteristics and Viral RNA Detection in Children With Coronavirus Disease 2019 in the Republic of Korea Presymptomatic Transmission of SARS-CoV-2 -Singapore Temporal dynamics in viral shedding and transmissibility of COVID-19 Age-Related Differences in Nasopharyngeal Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Levels in Patients With Mild to Moderate Coronavirus Disease Temporal profiles of viral load in posterior oropharyngeal saliva samples and serum antibody responses during infection by SARS-CoV-2: an observational cohort study Multisystem Inflammatory Syndrome in U.S. Children and Adolescents Epidemiology and transmission of COVID-19 in 391 cases and 1286 of their close contacts in Shenzhen, China: a retrospective cohort study COVID-19 in Children and the Dynamics of Infection in Families Transmission of SARS-CoV-2 in Australian educational settings: a prospective cohort study. Lancet Child Adolesc Health