Table 1. Requirements for further studies to improve the evidence base on the epidemiology of SARS-CoV-2 transmission by children.

Requirement	Elaboration
Diverse study designs	– Household studies – Seroprevalence and sero-incidence studies – Prospective cohort studies, e.g. in schools and daycares – (Cluster-) Randomized controlled trials – Case-control studies – Impact evaluation—time-series and quasi-experimental – Population surveillance studies including children – Clinical laboratory studies, including phylogenetic data – Basic laboratory and animal studies, experimental designs – Mathematical modeling studies
Avoidance and quantitative assessment of biases	– Selection bias in recruitment of study population or stratification – Information bias from missing data or measurement error – Confounding bias from unadjusted risk factors correlated with exposure – Survivor bias from loss to follow-up – Type II errors from significance testing with low power
Study population generalizability and representativeness	Pediatric sample must be drawn representatively from a population of interest to avoid biases and generalize inferences, and this population must be adequately described
Consideration of biological, behavioral and contextual factors	Collection of contextual variables, including social determinants of health such as neighborhood, cultural practices and political economic factors that impact risks and behavioral responses
Diagnostic—laboratory testing interpretation	– Understanding different diagnostic testing methods and their limitations – Distinguishing between presence of RNA and infectious virus – Recognizing the importance of the pre-analytical phase of sample collection – Statistical interpretation of test results, taking into account the test characteristics and the effect of prevalence – Correction for imperfect reference standard