Kevan Berkovitz (P), an infant, ingested a polio vaccine manufactured by Lederle Laboratories. Within a month, P had contracted polio and was unable to breathe without using a respirator. It was determined that P had contracted polio through this vaccine. P sued the United States (D) in Federal District Court. P claimed that D was liable for his injuries because D had acted wrongfully in licensing Lederle to produce the vaccine. P also claimed that these actions violated federal law and policy regarding the inspection and approval of polio vaccines. D moved to dismiss the suit, but the District Court denied the motion, holding that neither the licensing of the vaccine nor the release of that vaccine to the public was a 'discretionary function.' The Court of Appeals reversed. It rejected D's argument that the discretionary function exception bars all claims arising out of the regulatory activities of federal agencies. It stated that 'the discretionary function exception is inapplicable to nondiscretionary regulatory actions,' and noted that employees of regulatory agencies have no discretion to violate the command of federal statutes or regulations. It then held that federal law imposed no duties on federal agencies with respect to the licensing of poliovirus vaccines or the approval of the distribution of particular vaccine lots to the public. It then concluded that the licensing and release of polio vaccines were wholly discretionary actions and, as such, could not form the basis for suit against the United States. P appealed.