A new study looking at how COVID-19 affects people with asthma provides reassurance that having the condition doesn't increase the risk of severe illness or death from the virus.
George Institute for Global Health researchers in Australia analysed data from 57 studies with an overall sample size of 587,280. Almost 350,000 people in the pool had been infected with COVID-19 from Asia, Europe, and North and South America and found they had similar proportions of asthma to the general population.
The results, published in the peer-reviewed Journal of Asthma, show that just over seven in every 100 people who tested positive for COVID-19 also had asthma, compared to just over eight in 100 in the general population having the condition. They also showed that people with asthma had a 14 percent lower risk of acquiring COVID-19 and were significantly less likely to be hospitalised with the virus. There was no apparent difference in the risk of death from COVID-19 in people with asthma compared to those without.
Head of The Institute's Respiratory Programme, co-author Professor Christine Jenkins said that while the reasons for these findings weren't clear, there were some possible explanations, such as some inhalers perhaps limiting the virus' ability to attach to the lungs.
"Chemical receptors in the lungs that the virus binds to are less active in people with a particular type of asthma and some studies suggest that inhaled corticosteroids, commonly used to treat asthma, can reduce their activity even further," she said.
"Also, initial uncertainty about the impact of asthma on COVID-19 may have caused anxiety among patients and caregivers leading them to be more vigilant about preventing infection."
Lead author, Dr Anthony Sunjaya, added that while this study provides some reassurance about the risks of exposure to COVID-19 in people with asthma, doctors and researchers were still learning about the effects of the virus.
"While we showed that people with asthma do not seem to have a higher risk of infection with COVID-19 compared to those without asthma and have similar outcomes, we need further research to better understand how the virus affects those with asthma," he said.