The initial impression that paediatric SARS-CoV-2 infection is uncommon and generally mild has been replaced by a more nuanced understanding of infectious manifestations in children and adolescents across low-, middle-, and high-income countries and by demographic structure, with recognition of a widening disease spectrum. Critical knowledge gaps, especially in low- and middle-income countries remain, that have significant public policy and programme implications. Insufficient data disaggregated by age, geography and race/ethnicity are hindering efforts to fully assess prevalence of infection and disease in children and adolescents and their role in transmission. Potential biologic differences in susceptibility to infection and between children and adults need to be assessed. Determination of mother-to-child SARS-CoV-2 transmission during pregnancy or peripartum requires appropriate samples obtained with proper timing, lacking in most studies. Finally, predictors of disease progression, morbidity and mortality in children need to be determined particularly as the pandemic moves to low- and middle-income countries, where poor nutritional and health conditions and other vulnerabilities are more frequent among children than in higher-income settings. Countries, UN agencies, public health communities, donors and academia need to coordinate the efforts and work collectively to close the data and knowledge gaps in all countries (high-, middle- and low-income) for better evidence to guide policy and programme decision-making for children and COVID-19 disease.