WASHINGTON (AP) — U.S. health regulators say their response to the ongoing infant formula shortage was slowed by delays in processing a whistleblower complaint and test samples from the nation’s largest formula factory. The Food and Drug Administration on Tuesday published its first formal report detailing the factors that led to the shortage, which has forced the U.S. government to import formula from overseas. The report highlights several key problems at the regulatory agency. Those include unclear procedures for vetting whistleblower complaints about company violations. The agency also says it needs more funding and authority to regulate food manufacturers.