Israeli research: People with asthma 30% less likely to contract COVID-19

The findings were not dependent on age, gender or socioeconomic status.

An inhaler used to treat asthma (photo credit: NIAID/FLICKR)
An inhaler used to treat asthma
(photo credit: NIAID/FLICKR)
People with asthma could be as much as 30% less likely to contract the coronavirus, according to Israeli research that was accepted for publication in a peer-reviewed journal.
COVID-19 susceptibility in bronchial asthma,” which is slated to be published in the Journal of Allergy and Clinical Immunology this month and which The Jerusalem Post reviewed, shows that contrary to what has been assumed by many medical professionals up until now, people with bronchial asthma are less likely to get COVID-19.
The findings were not dependent on age, gender or socioeconomic status.
There are three hypotheses for why asthma patients might not catch COVID, explained Dr. Eugene Merzon, head of the Department of Managed Care in Leumit Health Services, who helped lead the study.
The first is physical: Respiratory allergy is associated with significant reductions in angiotensin-converting enzyme 2 (ACE2) receptors in the lungs, the protein that provides the entry point for COVID-19 to hook into and infect human cells.
The second is sociological: People with asthma are more likely to suffer from severe cases of COVID-19. As such, said Merzon, they are more likely to adhere to Health Ministry instructions, including wearing masks, social distancing and maintaining good hygiene.
The study recommended that further studies be done to better define how chronic comorbidity might modify compliance with public health measures to limit the effects of pandemics.
Finally, treatment for asthma with inhaled corticosteroids (ICSs) could reduce the likelihood of getting the virus.
Merzon explained that most people with chronic asthma use inhalers. Studies have shown that ICS use might reduce replication of COVID-19.
“The recommendation is that these patients make sure they continue taking their medication” during the pandemic, Merzon said. The paper also advised that in general, physicians should continue to treat asthma according to existing asthma guidelines and recommendations.
Until now, bronchial asthma has not been adequately assessed in relation to coronavirus disease, the authors wrote in their paper.
This research was a retrospective, population-based, cross-sectional study that utilized data from Leumit’s nationwide health fund database of 725,000 members. It specifically included all health fund enrollees who had been tested for COVID-19 from February 1 to June 30, 2020 – some 37,569 people, including 2,266 who tested positive.
Asthma was found in 153 or 6.75% of COVID-19 positive patients and in 3,388 or 9.62% of those who tested negative.
Previous epidemiological reports from China and Italy revealed that few patients with COVID-19 had asthma, the paper notes. Asthma was reported in 9% of hospitalized patients with COVID-19 in New York and 14% in the United Kingdom, the authors added.
“However, all these prevalence data were derived from the COVID-19 inpatient population,” the researchers explained. “Therefore, the prevalence of asthma may be different in outpatient patients with COVID-19.”
Moreover, they said that in previous severe acute respiratory syndrome outbreaks, such as SARS in 2003, patients with asthma appeared to be less susceptible to the coronavirus infection, which also uses ACE2 as an entry receptor. However, “reported entry receptors for most other coronaviruses do not include ACE2 and they exacerbate asthma upon infection.”
Going forward, Merzon said the study could play a role in helping personalize recommendations for different cohorts of the public with preexisting conditions and allow health professionals to better differentiate between those patients who are at higher and lower risk of contracting the virus, rather than just of those experiencing severe symptoms.
Merzon worked with doctors Ilan Green, Shlomo Vinker, Avivit Golan-Cohen and Eli Magen on the study.