The original anthrax vaccine was developed in the 1950s and was first produced on a large scale by Merck. The BioPort Corporation in Michigan is now the sole facility in the United States capable of producing the vaccine. The Food and Drug Administration (FDA) licenses biological products and their production facilities. The manufacturer is required to comply with current good manufacturing practices, which regulate personnel, buildings, equipment, production controls, records, and other aspects of the vaccine manufacturing process. When there is a major change in the manufacturing process, the manufacturer must submit evidence to FDA showing that the change does not have any adverse effects. The manufacturer must also ensure that the quality of the product is maintained. In the case of the anthrax vaccine, the Michigan facility did not notify FDA of several changes to the manufacturing process in the early 1990s, and no specific studies were done to confirm that vaccine quality was not affected. FDA inspections found several deficiencies, many of which were not corrected in a timely manner.