1. WHO Coronavirus (COVID-19) Dashboard,2021
2. Risk factors for severe and critically ill COVID-19 patients: a review;Gao;Allergy,2021
3. Epidemiology of COVID-19 among children in China;Dong;Pediatrics,2020
4. Evolution of the immune system in humans from infancy to old age;Simon;Proc. Biol. Sci.,2015
5. A systematic review and meta-analysis of children with coronavirus disease 2019 (COVID-19);Cui;J. Med. Virol.,2021