Early in the coronavirus pandemic, public health authorities warned that those with asthma may have a higher risk of developing severe illness as a result of COVID-19. Now, however, a study funded by the National Institutes of Health (NIH) aims to investigate whether coronavirus infection rates differ among kids with asthma compared to children who don't have the chronic lung condition. News of the NIH-funded study comes weeks after researchers at the University of Wisconsin School of Medicine and Public Health found that adults and children with respiratory allergy and allergic asthma may actually have a decreased susceptibility to infection.
Researchers have already begun enrolling participants in a study entitled Human Epidemiology and Response to SARS-CoV-2 (HEROS), which seeks to uncover the rate of coronavirus infection in U.S. children and their families. But that isn't all the HEROS study will look at; it will also seek to determine what percentage of COVID-19 positive children develop symptoms vs those who are asymptomatic and examine whether infection rates differ between children with asthma or other allergic conditions compared to children without these conditions.
"Asthma is a risk factor for significant respiratory morbidity from respiratory viruses, even respiratory viruses that cause the common cold, like rhinovirus," Dr. Tina V. Hartert, the HEROS study's leading researcher, director of the Center for Asthma and Environmental Sciences Research, and Lulu H. Owen Chair in Medicine at the Vanderbilt University School of Medicine in Nashville, tells Romper. "Thus the fact that we are not seeing asthma as a significant co-morbidity among patients with severe COVID-19 in many of the case series is unusual, particularly as it is a very common chronic disease in both adults and children. In children it is typically one of the most common causes of childhood hospitalizations overall."
Because of asthma's history with respiratory viruses, public health officials across the world were quick to classify it as a potentially high-risk underlying condition for coronavirus infection when infections first began to be reported. The Centers for Disease Control and Prevention (CDC) notes that, "people with moderate to severe asthma may be at higher risk of getting very sick from COVID-19." Meanwhile, the World Health Organization states that those with pre-existing medical conditions, such as asthma, diabetes, heart disease, "appear to be more vulnerable to becoming severely ill" with COVID-19.
However, Hartert tells Romper that it's been "surprising" to see that "asthma has not consistently been a risk factor in the clinical series." "It is additionally unusual to not see significant [coronavirus-related illness] in children given that after obesity, asthma is the second most common chronic disease in children in the US," Hartert says.
According to data from the CDC, more than 5.5 million children had asthma in the United States in 2018. Hartert tells Romper the HEROS study will examine all different types of asthma, including allergic or atopic asthma, which is considered to be one of the most common types of asthma in children.
A study published in Journal of Allergy and Clinical Immunology last month found that the reduced angiotensin-converting enzyme-2 (ACE2) gene expression that comes along with having allergic asthma and respiratory allergies could provide some some kind of protection against COVID-19. In that study, researchers from the University of Wisconsin School of Medicine and Public Health found that children with asthma and high levels of allergy had the lowest ACE2 expression, which could explain why smoking, diabetes, and hypertension, all of which are associated with a higher expression of ACE2, have proven to be high risk for COVID-19 while asthma has not.
Hartert hopes the HEROS study can further research the relationship between asthma and COVID-19. "If asthma is not a risk factor, or if it turns out to be protective, it could also be that it is the medications used to treat asthma, rather than the disease itself, that is protective," she tells Romper. "This will also be really important to determine and is a focus of the HEROS study."
For the moment, however, both the WHO and CDC continue to classify asthma as a potentially high risk underlying condition — something Hartert agrees with. "Until we know, however, I think it is safest to assume, as with other respiratory viruses, that persons with asthma may be at increased risk," she tells Romper. "But it's a question that we must answer as it may provide important clues about the virus and potential preventive strategies."
If you think you’re showing symptoms of coronavirus, which include fever, shortness of breath, and cough, call your doctor before going to get tested. If you’re anxious about the virus’s spread in your community, visit the CDC for up-to-date information and resources, or seek out mental health support. You can find all of Romper’s parents + coronavirus coverage here, and Bustle’s constantly updated, general “what to know about coronavirus” here.
Jackson DJ, Busse WW, Bacharier LB, Kattan M, O’Connor GT, Wood RA, Visness CM, Durham SR, Larson D, Esnault S, Ober C, Gergen PJ, Becker P, Togias A, Gern JE, Altman MC, Association of Respiratory Allergy, Asthma and Expression of the SARS-CoV-2 Receptor, ACE2, Journal of Allergy and Clinical Immunology (2020), doi: https://doi.org/10.1016/j.jaci.2020.04.009
Tina V. Hartert, M.D., M.P.H., director of the Center for Asthma and Environmental Sciences Research, vice president for translational research, the Lulu H. Owen Chair in Medicine, and professor of medicine at the Vanderbilt University School of Medicine.