Higher Covid vaccination rates could help protect children against asthma attacks, according to research.
While previous studies show that vaccination helps prevent Covid 19 illness, the authors believe this is the first study to assess whether Covid inoculation is associated with reductions in children’s asthma symptoms, by preventing viral illness in children with asthma.
US researchers examined parent-reported asthma symptom prevalence in more than 150,000 children in the National Survey of Children’s Health between 2018-19 and 2020-21, broken down by US state.
The data was then compared with the proportion of people aged five years and older who were vaccinated in 2020-21, as well as age-adjusted Covid mortality rates and any face mask requirements in enclosed spaces.
Researchers then calculated any changes in reported childhood asthma symptom prevalence and found that Covid inoculation may help protect asthmatic children against Covid infection and could also protect against other coronaviruses such as the common cold.
With each increase of 10 percentage points in Covid vaccination coverage in US states, there was a 0.36 percentage point reduction in the rates of child asthma symptoms as reported by their parents, according to the study, published in Jama Network Open.
Dr Andy Whittamore, the clinical lead at Asthma + Lung UK, said: “Two million children in the UK live with asthma. Infections such as Covid-19 and flu can cause irritation and inflammation in the airways of people with asthma. This can lead to an increase in mucus and narrowing of the airways, which in turn can cause symptoms such as breathlessness, wheeze, tightness in the chest and coughing and potentially trigger an asthma attack.
“So it’s important for children with asthma to get any vaccinations they are eligible for, such as flu, to keep them safe. It’s also vital to make sure your child takes their preventer inhaler daily and always has their reliever inhaler with them.”
Every child with asthma should have an annual asthma review with a healthcare professional and an asthma action plan to explain which medicines they needed to take every day to cut their risk of an asthma attack and what to do if their symptoms were getting worse, he added.
Dr Matthew Davis, the chief scientific officer at Nemours Children’s Health and the lead author of the study, said: “We found that states with higher population-level vaccination rates against Covid-19 were more likely to have larger decreases in the proportion of parents reporting that their children had asthma symptoms, compared to prior to the pandemic.”
In contrast, the study also found that reductions in state-level parent-reported child asthma symptoms were not associated with levels of Covid infections in the state or whether the state had face mask requirements in 2021.
Asthma flares are often caused when a person with a history of the condition develops a viral respiratory infection. Studies of flu vaccination over the past 50 years indicate that asthmatics who are vaccinated against flu are less likely to have asthma attacks that require hospitalisation.
Higher Covid vaccination rates might be linked to lower rates of children’s asthma symptoms in two main ways, the study suggested. First, higher vaccination coverage in the general population might indicate that children with asthma were more likely to be vaccinated against Covid than children with asthma in other states with lower Covid vaccination coverage. Second, higher inoculation rates might make it less likely that viruses would spread from person to person in the community, thereby reducing the risk to asthmatic children.
Responding to the findings, however, Seif Shaheen, a professor of respiratory epidemiology at Queen Mary University of London, said the results should be treated with “extreme caution”, as there were likely to be multiple factors associated with childhood asthma and the likelihood of being vaccinated that could confound the findings, but these studies were “useful for generation of hypotheses to be tested in more rigorous observational studies of individuals”.
