“We have stepped up and are killing ourselves to do everything we can,” Kessler said.

Perrigo’s formula manufacturing facilities in Ohio and Vermont are now running at 115% of capacity, Kessler said.

At the request of the U.S. Food and Drug Administration, Perrigo is focusing on four items, the store-brand versions of Similac Pro Sensitive and Pro Advance and Enfamil Gentle Ease and Infant, Kessler said.