The company at the center of quality problems that led Johnson & Johnson to discard 15 million doses of its coronavirus vaccine has a string of citations from U.S. health officials for quality control problems. Little-known pharmaceutical company Emergent BioSolutions was a key to Johnson & Johnson’s plan to deliver 100 million doses of its vaccine to the United States by the end of May. But records obtained by The Associated Press show that Emergent has been cited repeatedly by the Food and Drug Administration for problems ranging from poorly trained employees to cracked vials and mold around one of its facilities.