Given asthmatic children’s susceptibility to respiratory illnesses like the flu, it was assumed they’d be more prone to severe COVID-19 infection. But a new Australian study suggests that, compared to children who don’t have asthma, those with the condition are not at greater risk of serious COVID infection.
Many chronic conditions – cancer, diabetes, obesity, high blood pressure and heart disease, for example – are considered risk factors for COVID-19 infection and can complicate recovery.
Because respiratory infections such as influenza commonly exacerbate asthma symptoms, it was anticipated that asthmatic children, especially, would be predisposed to severe COVID-19. But a recently published large study by researchers at the University of New South Wales (UNSW) Sydney suggests this may not be the case.
“Children with asthma are generally more susceptible to respiratory illnesses like influenza, so it was initially thought they may be vulnerable to severe infection from the COVID virus,” said Nusrat Homaira, corresponding author of the study.
“But our study, based on a substantial sample of children across multiple waves of the pandemic, indicates children with asthma were not at higher risk of severe COVID than children without asthma,” added Mei Chan, the study’s lead author.
The researchers analyzed de-identified data from the medical records of 18,932 children under 17 with a positive PCR test who sought care from The Sydney Children’s Hospitals Network between January 2020 and May 2022. Of those, 1,025 (5.4%) had a prior diagnosis of asthma.
They compared children with previously diagnosed asthma to those without asthma based on their risk of developing COVID-19 and disease severity, measured by length of hospital stay, admission to an intensive care unit (ICU), whether mechanical ventilation was required and mortality.
Of 72 children with COVID-19 who needed intensive care, those with asthma were not at great risk of being admitted to ICU during any of the pandemic waves, that is, Alpha, Delta, and Omicron. Mechanical ventilation was reported in 19 children with COVID-19, only two of which had asthma. Eleven children died during the study – only one was certified as dying from COVID-19 – and none of the deaths were in children with asthma.
“We looked at different markers of disease severity, and although the group of children with asthma generally required a longer duration of hospitalization, they were not at greater risk of COVID severity in terms of ICU admissions, mechanical ventilation use, or mortality compared to those without asthma at any stage of the outbreak,” said Homaira.
The researchers did find that the length of hospital stay for asthmatic children increased by 1.17 days when Omicron was the dominant strain.
“Children with COVID were less likely to be asthmatic during the early stages of the pandemic,” Homaira said. “With the emergence of the Omicron variant, we observed an increase in the risk of COVID infection among children with asthma compared to those without.”
The researchers say it’s important to remain vigilant, particularly when new strains emerge.
“We need to keep monitoring the emerging variants of COVID-19 and encouraging children, especially those with underlying chronic conditions, to keep up to date with their vaccinations as we know they can help reduce the risk of severe respiratory infections,” Homaira said.
The study was published in The Journal of Asthma and Allergy.
Source: UNSW Sydney