Asthma may not increase the risk of severe illness or death from Covid-19, a new study suggests.

The review of studies on 587,000 people showed that people with asthma had a 14 per cent lower risk of getting Covid-19 and were significantly less likely to be hospitalised with 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,” said lead author Anthony Sunjaya from the University of New South Wales in Australia.

For the study, published in the peer-reviewed Journal of Asthma, the team 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 showed 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. Previous findings have shown that people with chronic respiratory conditions like asthma were reported to be at greater risk during the Middle East Respiratory Syndrome (MERS) outbreak, caused by a virus with a similar structure.

“Respiratory infections like those caused by coronaviruses can exacerbate asthma symptoms and corticosteroid treatment may increase susceptibility to Covid-19 infection and its severity,” Sunjaya said.

However, this study using the best evidence available on the risk of infection, severe illness — requiring admission to ICU and/or ventilator use — and death from Covid-19 in people with asthma finds “no significant difference” of people with asthma being at higher risk, the team said.