(Reuters) -The U.S. Food and Drug Administration on Monday gave full approval to Moderna Inc’s COVID-19 vaccine for people age 18 and older, making it the second fully approved vaccine for the virus. The Moderna vaccine has been authorized for emergency use in the United States since December 2020, and will now be sold under the brand name Spikevax. Pfizer and BioNTech’s COVID-19 shot using similar technology received full approval in the United States last year for people aged 16 and older after also first gaining emergency authorization. Nearly 75 million people have already received Moderna…