id	author	title	date	pages	extension	mime	words	sentences	flesch	summary	cache	txt
cord-289349-imkgpwn0	Qiu, Li	Strong immunity in the early two years of age links to frequent immunization of routine vaccines	2020-08-08		.txt	text/plain	2040	121	52	In this retrospective study, 25 patients under 10 years old were selected from a total of 186 laboratory-confirmed COVID-19 patients (Materials and methods, Fig. S1 , and Table S1 online). The patient age distribution revealed that children of all ages are susceptible to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection (Fig. 1a) . Because pediatric COVID-19 patients aged under 2 years were found to have shorter recovery times, we next further analyzed the clinical differences between children under and over 2 years old; several variables were compared between these two groups (Table S7 online). However, a previous epidemiological study revealed that the incidence of seasonal coronavirus infection in children under one year old is not significantly different from that in older children [15] . Pre-existing cross-reactive T-cell immunity to infections or vaccinations alters subsequent T-cell responses to antigens of unrelated pathogens [18] [19] [20] , thus frequently contributing to a protective or pathogenic role in infectious diseases [18, 20] .	./cache/cord-289349-imkgpwn0.txt	./txt/cord-289349-imkgpwn0.txt