A recall of the emergency anti-allergy medicine EpiPen is expanding to the U.S. and other markets in North America, Europe, Asia and South America because the allergy shots may not work.

The notice issued Friday by Mylan N.V. expands upon warnings made earlier this month after two reports of the device failing. The recall now covers 13 lots distributed from December 2015 through July 2016.

The problems could be potentially life-threatening, although Mylan described the incidence of the defects as “extremely rare.”