Walgreens Boots Alliance Inc. expanded a partnership with Kaleo Inc. to include the company’s epinephrine auto-injectors for infants and toddlers in the drugstore chain’s pharmacies amid a national shortage of the emergency allergy shots.

EpiPens and other autoinjectors filled with epinephrine to treat severe allergic reactions may still be potent enough to work many months past their labeled expiration date, according to a study that concludes patients might need expensive refills less often.