Immunotherapy tablets are starting to edge out shots as a treatment for allergies. And it looks like the pills can help reduce the frequency of asthma attacks, too. Scientists reported Tuesday that immunotherapy tablets for dust mite allergy reduced the risk of an attack in people with moderate to severe asthma. The results were published in JAMA, the journal of the American Medical Association.

Allergies are a big trigger of asthma, and allergy to dust mites, tiny insects that live in homes, is the most common allergic asthma trigger. The 693 people who completed the study had asthma that wasn’t well controlled by inhaled corticosteroids. Half of the participants took a pill made of dust-mite allergen daily, letting it dissolve under the tongue. The immunotherapy tablet significantly reduced the risk of a moderate or severe asthma attack. It’s the first time sublingual immunotherapy tablets (often referred to as SLIT) have been tested as an asthma treatment, according to Dr. J. Christian Virchow, a professor of pulmonology at the University of Rostock in Germany and lead author of the study.

The tablets typically are to be taken daily for three years, with protection from symptoms continuing after that. They’re about as effective as allergy shots, and less likely to prompt anaphylactic shock. The risk of a rare life-threatening reaction is one big reason that allergy shots are given at a doctor’s office. None of the participants in the study had serious side effects. Some had local side effects like swelling of the lips and tongue or an itchy throat.