COVID-19 in Newborns and Infants-Low Risk of Severe Disease: Silver Lining or Dark Cloud?

Abstract

One hundred years after the 1918 influenza pandemic, we now face another pandemic with the severe acute respiratory syndrome-novel coronavirus-2 (SARS-CoV-2). There is considerable variability in the incidence of infection and severe disease following exposure to SARS-CoV-2. Data from China and the United States suggest a low prevalence of neonates, infants, and children, with those affected not suffering from severe disease. In this article, we speculate different theories why this novel agent is sparing neonates, infants, and young children. The low severity of SARS-CoV-2 infection in this population is associated with a high incidence of asymptomatic or mildly symptomatic infection making them efficient carriers. KEY POINTS: · There is a low prevalence of novel coronavirus disease in neonates, infants, and children.. · The fetal hemoglobin may play a protective role against coronavirus in neonates.. · Immature angiotensin converting enzyme (ACE2) interferes with coronavirus entry into the cells..

Fig. 1

( A ) A pie chart showing distribution of population in United states based on age as adults (>19-year olds), pediatrics (1–18 years) and infants (<1-year olds). ( B ) The reported COVID-19 cases in adults, pediatrics and infant population in United States. Blue represents adults over 19-year olds, orange represents pediatric cases age 0–18-year olds, and gray represents infants <1-year olds. COVID-19, novel coronavirus disease 2019.

Fig. 2

A schematic showing possible factors resulting in low incidence and less severity of coronavirus disease (COVID-19) in pediatric age group. Children in generally have healthier lungs and are less exposed to smoke and pollution. The maturity, binding ability and function of Angiotensin converting enzyme (ACE2) receptors required by severe acute respiratory syndrome–coronavirus-2 (SARS-CoV-2) to enter the cells, is lower in children resulting in minimal lung injury. More extensive exposure to other viruses may provide cross immunity to SARS-COV2. A cytokine storm or systemic inflammatory response syndrome that results in inflammation and fluid buildup leading to respiratory distress is not well developed in children. More efficient T-cells response in children may be another reason for superior outcomes. SARS-CoV-2 proteins appear to attack β hemoglobin chains and “capture” porphyrins inactivating gas exchange capabilities of hemoglobin (Hb) and interfering with heme anabolic cycle. Young infants, with fetal Hb (α2γ2) without β chains, may potentially be less susceptible to SARS-CoV-2 mediated effects on Hb. Image courtesy: Satyan Lakshminrusimha .