The role of children in the spread of SARS-CoV-2 remains highly controversial. To address this issue, we performed a meta-analysis of the published literature on household SARS-CoV-2 transmission clusters (n=213 from 12 countries). Only 8 (3.8%) transmission clusters were identified as having a paediatric index case. Asymptomatic index cases were associated with a lower secondary attack in contacts than symptomatic index cases (estimate risk ratio [RR], 0.17; 95% confidence interval [CI], 0.09-0.29). To determine the susceptibility of children to household infections the secondary attack rate (SAR) in paediatric household contacts was assessed. The secondary attack rate in paediatric household contacts was lower than in adult household contacts (RR, 0.62; 95% CI, 0.42-0.91). These data have important implications for the ongoing management of the COVID-19 pandemic, including potential vaccine prioritization strategies.

BACKGROUND: Since its identification on the 7 th of January 2020, SARS-CoV-2 has spread to more than 180 countries worldwide, causing >11,000 deaths. At present, viral disease and transmission amongst children is incompletely understood. Specifically, there is concern that children could be an important source of SARS-CoV-2 in household transmission clusters. METHODS:We performed an observational study analysing literature published between December 2019 and March 2020 of the clinical features of SARS-CoV-2 in children and descriptions of household transmission clusters of SARS-CoV-2. In these studies the index case of each cluster defined as the individual in the household cluster who first developed symptoms.FINDINGS: Drawing on studies from China, Singapore, South Korea, Japan, and Iran a broad range of clinical symptoms were observed in children. These ranged from asymptomatic to severe disease. Of the 31 household transmission clusters that were identified, 9.7% (3/31) were identified as having a paediatric index case. This is in contrast other zoonotic infections (namely H5N1 influenza virus) where 54% (30/56) of transmission clusters identified children as the index case.

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