AstraZeneca  (NYSE:AZN)  is starting Phase 3 trials of its experimental coronavirus vaccine in the U.S., becoming the third company to start late-stage trials to prevent COVID-19. Trial centers across the nation are recruiting up to 30K adults aged 18 years or over. AstraZeneca’s vaccine, known as AZD1222, was developed in partnership with Oxford University and has the backing of the U.S. government. Rivals Moderna  (NASDAQ:MRNA)  and Pfizer  (NYSE:PFE)/BioNTec  (NASDAQ:BNTX)  already have Phase 3 trials under way, also with federal funding.