Box-by-box, employees for Irving-based McKesson have been preparing for months for the FDA’s endorsement of Moderna’s vaccine. If emergency use is granted, McKesson would ship Moderna's vaccine at the government's direction across the country from distribution centers in Memphis and the Louisville area. Supply kits will be included in shipments created by more than 1,000 McKesson employees hired for the effort. Each kit contains everything needed to give out 100 doses. So far, the kits prepared support more than 100 million doses. Allen Fire Chief Jonathan Boyd is part in Moderna's clinical trial. He said he felt mild side effects after his second shot in late September.