The Food and Drug Administration has approved a new, US-manufactured flu vaccine, which is expected to increase the domestic capacity for making shots by 50 million doses.

Health officials have been looking to increase flu vaccine manufacturing in the U.S. since most of the shots are made in other countries. The announcement on June 17 is expected to give the FDA increased oversight over quality and quantities of the vaccine, which is recommended for heart and stroke patients.

The vaccine, called FluCelVax, is made using dog cells cultured in a lab. The technology is expected to cut down response time in the case of an emerging health threat to weeks instead of months, according to Novartis, which operates the vaccine facility.