The study, which CHOC doctors and scientists say is the most comprehensive of its kind to date, also found that inhaled corticosteroids – the first-line therapy for youth with persistent asthma – reduces the binding ability of the SARS-Cov-2 virus, this hijacking its ability to infect healthy cells.
“Our study confirmed what we all assumed: that controller therapy attenuates SARS-Cov-2 asthma exacerbations,” said Dr. Iris Kim, lead author of the study, published in June 2023 in Annals of Allergy, Asthma Immunology.
A related CHOC study published in 2022 found that asthma in children may worsen after COVID-19 infection.
Both studies debunk some assumptions held in the months after the pandemic hit in March 2020.
Children with asthma enjoyed a dramatic reduction in asthma-related issues during the first year of the pandemic, but that was largely because of stay-at-home orders, masking, and other public health measures, CHOC researchers found.
Regarding the latest research, there was some fear in the medical community that taking inhaled corticosteroids would worsen COVID-19 symptoms because the medications suppress immunity, and lower immunity could promote SARS-Cov-2 replication and increase the risk of secondary infection.
However, Dr. Kim and her fellow 2023 study authors – pediatric allergist Dr. Stanley Galant; Dr. Christine Chou, a former physician in the CHOC Wellness on Wheels program (formerly known as Breathmobile); Louis Ehwerhemuepha, Ph.D., who leads CHOC’s research data science program; and biostatistician Tricia Morphew – found that the opposite was true.
Based on data they culled from nearly 62,000 asthmatic children at 108 pediatric healthcare systems across the Unites States, inhaled corticosteroids were associated with reduced asthma exacerbations in children with COVID-19 (as well as those who tested negative for the virus).
This finding “was most reassuring,” the authors wrote in the 2023 study.
“This was an extremely important finding,” said Dr. Galant, founder and former director of the recently renamed CHOC Wellness on Wheels.
More studies to come
In addition to a large sample, the 2023 study represented diverse ethnic populations, Drs. Kim and Galant said.
The children whose data was examined for the 2023 study received a SARS-CoV-2 PCR test from March 2020 to February 2021. Researchers looked at data six months before the kids tested positive for the virus as well as six months after they became infected.
Prior similar studies conducted by other pediatric hospitals failed to have adequate study controls because they only examined children after they tested positive for the virus and failed to also include the six-month period before the onset of the infection, Dr. Kim said.
The CHOC team will pursue more studies on asthma and COVID-19, Dr. Galant said. One idea, he said, is to determine whether having asthma is a risk of contracting SARS-CoV-2.
“What are the subtypes of asthma that are likely to result in severe COVID-19?” Dr. Galant asked. “That’s a question I’ve been wondering about. So far, our research has looked at the effects of COVID-19 on asthma. What about the flip side?”
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