Kids with allergies less likely to get SARS-CoV-2

The prevalence of hypertension, diabetes, cardiovascular diseases, and respiratory diseases are high-risk factors for severe coronavirus disease 2019 (COVID-19). COVID-19, which is caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is a respiratory disease that has infected more than 195 million people worldwide and caused the deaths of over 4.18 million as of July 29, 2021.

Asthma and COVID-19

“There is an ongoing need to investigate the association between asthma and SARS-CoV-2 infection in population-based studies of children and adolescents, among whom asthma is the most common chronic medical condition and a leading cause of hospitalization.”

Study: Asthma and the Risk of SARS-CoV-2 Infection Among Children and Adolescents. Image Credit: New Africa / Shutterstock.com

Several studies have also suggested that individuals with asthma are less susceptible to SARS-CoV-2 infection and are at low risk of severe COVID-19. To date, asthmatic patients have represented only 1-2% of hospitalized COVID-19 patients across the world. Additionally, asthma was less prevalent among individuals testing positive for SARS-CoV-2 compared to individuals testing negative for the virus.

Notably, these studies focused primarily on adults. In this context, researchers from Duke University were interested in determining the COVID-19 infection risk in children between the ages of 5 and 17 with asthma.

To this end, the researchers evaluated the risk of SARS-CoV-2 infection by asthma status in children receiving health care in Durham County, North Carolina. They also evaluated how the use of inhaled corticosteroids (ICS) and the presence of comorbid atopic (sensitivity to allergens) diseases modified the association between asthma and the risk of SARS-CoV-2 infection.

Study results

The study included a cohort of 49,455 children and was conducted in the Duke University Health System (DUHS) during an eight-month period from March 1, 2020

to October 31, 2020. Of these children, 6,515 (13.2%) met the definition for asthma. Taken together, 1.1% of children tested positive for SARS-CoV-2 infection during the study period, of which 66 (1.0%) children had asthma and 498 (1.2%) children did not have asthma.

The researchers of the current study, which was published on the preprint server medRxiv*, found that asthma was associated with a lower risk of 35% of SARS-CoV-2 infection among children. This reduced risk remained true among asthmatic children who were prescribed an inhaled corticosteroid or had comorbid atopic diseases.

This finding suggests that these factors affect the susceptibility to SARS-CoV-2 infection. Interestingly, the researchers also found that none of the children with asthma who acquired SARS-CoV-2 had required hospitalization for COVID-19.

It was also noted that positive SARS-CoV-2 results were associated with non-White asthmatic children with self-pay insurance and from more deprived neighborhoods.

No evidence was found to support that asthma predisposes children to severe COVID-19, which is a helpful observation for healthcare providers and a relief for parents of asthmatic children.

Study implications

While previous research suggests that the use of ICS increases the risk of general respiratory tract infections before COVID-19, the current data shows that these medications do not increase susceptibility to SARS-CoV-2 infection or the severity of COVID-19 among children. On the contrary, this study indicates that ICS use may contribute to a lower risk of SARS-CoV-2 infection among children.

The researchers, therefore, emphasized the importance of continuing these medications during the ongoing COVID-19 pandemic. The use of ICS and comorbid atopic diseases may contribute to the association between asthma and SARS-CoV-2 susceptibility.

Several factors including a reduced expression of the SARS-CoV-2 host receptor angiotensin-converting enzyme 2 (ACE2), suppression of interferons, and relatively less exposure of asthmatic children to SARS-CoV-2 and risk mitigation strategies, may all contribute to the reduced susceptibility of asthmatic children to COVID-19.

Conclusion

Asthma is not associated with worse outcomes among children and adolescents with COVID-19. Evidently, children with asthma are at a lower risk of SARS-CoV-2 infection and generally have mild symptoms of COVID-19. Thus, the researchers strongly recommend that children with asthma continue their treatment and asthma action plans during the ongoing COVID-19 pandemic.

*Important Notice

medRxiv publishes preliminary scientific reports that are not peer-reviewed and, therefore, should not be regarded as conclusive, guide clinical practice/health-related behavior, or treated as established information.

Written by

Dr. Ramya Dwivedi

Ramya has a Ph.D. in Biotechnology from the National Chemical Laboratories (CSIR-NCL), in Pune. Her work consisted of functionalizing nanoparticles with different molecules of biological interest, studying the reaction system and establishing useful applications.