Inhalers, the kind used by millions of Americans for treating asthma attacks, may come with an unexpected side effect. Newly published research suggests that this form of bronchial therapy may temporarily lower immunity in children.

Pediatricians at the Universite de Montreal discovered this effect after giving asthmatic children and teens small, measured doses of antigens, which are particles that cause an immune reaction.

Multiple pediatric participants exhibited a weakened response to the exposure, based on their blood levels of antibodies. Researchers said that inhaled corticosteroids may be to blame, although they added that the risk is small.

“The very rare occurrence of severe infectious disease is reassuring and would suggest that the window of risk is very small and only applies to exposure to a new antigen,” said lead author Francine Ducharme.

Whether an individual has asthma or not, proper nutrition is an essential part of keeping the immune system strong. Adults may consider investing in multivitamins to make sure that they are not exacerbating existing allergies.

More than 17 million American adults have asthma, according to the Centers for Disease Control and Prevention (CDC).