BACKGROUND Milder symptoms were observed in children with COVID-19 . However, whether this also holds true for neonates is not known .
METHODS The clinical data of a total of 3213 patients aged two years or below, including 749 neonates, in Brazil nationwide were studied . Comparisons were made between neonate and infant patients by conducting statistical tests .
RESULTS Neonates appeared to bear more severe clinical courses . In addition to higher case fatality rates, newborns with COVID-19 had much shorter time from symptom onset to death and longer time from symptom onset to discharge . Dyspnoea, sore throat and cough were more prominent in neonate patients, suggestive of both upper and lower respiratory tract infection, as opposed to upper respiratory tract symptoms mostly observed in children .
CONCLUSION Findings suggested that trained immunity provides a possible explanation because the innate immune system in newborns is not``well-trained"while that in adult tends to hyperactive.