Infants more likely to get hospitalized as coronavirus can get severe due to weak immune system
Data from the US paints a dire picture: children under the age of one are developing a severe form of COVID-19 compared to older children.
Of the cases reported in children aged between 0 and 18 years, only 15% occurred in infants. However, despite that, infants suffered the most. US hospitals admitted 147 children, as of April 2, 2020. Among these patients, 59 were infants, according to a report from the Centers for Disease Control and Prevention (CDC).
But why are more infants getting hospitalized? According to an expert, infants have a weaker immunity. “The first year of life, children don’t have the same robust immune response that older children and adults do," Dr Yvonne Maldonado, professor of pediatrics at Stanford University School of Medicine and chair of the committee on infectious diseases at the American Academy of Pediatrics, told Time.
This, however, does not mean the new coronavirus is sparing older children. Though a majority of them develop the mild disease, some suffer from severe conditions. Both data from other countries have supported this.
Three older children have died so far. "We are seeing more and more younger individuals who are experiencing severe disease,” Dr. Maria Van Kerkhove, head of the WHO’s emerging diseases and zoonosis unit, said at a news briefing from the organization’s Geneva headquarters. “We’ve seen some data from several countries across Europe where people of younger age have died,” she added.
The data suggest that doctors need to keep a close watch on children. Although most cases reported among children to date have not been severe, clinicians should maintain a high index of suspicion for COVID-19 infection in children and monitor for progression of the illness, particularly among infants and children with underlying conditions," the report reads.
The CDC report said hospitalizations were common among those with underlying conditions. These underlying conditions include asthma and diabetes. According to Dr. Aaron Milstone, a pediatrician at the Johns Hopkins Children’s Center, children with asthma may have more severe symptoms from COVID-19 or any other respiratory disease, including the flu. He added that children with poorly-controlled sugar levels may have a weak immune system, making them susceptible to the disease.
The report also throws light on sex differences among children: the coronavirus inflicts more damage in males than females. According to the CDC report, a majority — 57% — of coronavirus positive children were male.
Data on adults also show a similar trend. In China, scientists studied case reports of 44,000 patients and found that men had a higher death rate. While scientists still do not know what makes women less susceptible, they think hormones or lifestyle factors are at play.
Why some develop severe disease?
At the moment, scientists do not know why the disease develops into a severe illness in some individuals but not others. Researchers across the world are trying to understand the virus's behavior, Van Kerhove said.
At the moment, scientists are formulating theories and testing them. One theory gaining traction is the role of genes. For example, scientists are looking at whether a gene called ACE2 has a part to play. People tend to have different versions of the gene and one particular variation might allow the virus an easy entry into human cells.
We see huge differences in clinical outcomes and across countries. How much of that is explained by genetic susceptibility is a very open question,” geneticist Andrea Ganna, of the University of Helsinki’s Institute for Molecular Medicine Finland, told Science Magazine.
Another theory is to test whether people developing severe conditions have an overactive immune system. This means while fighting the disease, the immune system of healthy people can overreact, resulting in more complications.
Some scientists also believe that a high total amount of virus a person has inside them or viral load could be to blame. Explaining how a high viral load can impact humans, Dr Edward Parker of the London School of Hygiene and Tropical Medicine, told The Independent: “After we are infected with a virus, it replicates in our body’s cells. For COVID-19, early reports from China suggest the viral load is higher in patients with more severe disease, which is also the case for SARS and influenza."