Oct 20 (Reuters) - The U.S. Food and Drug Administration on Wednesday authorized booster doses of the COVID-19 vaccines from Moderna Inc and Johnson & Johnson, and said Americans can choose a different shot than their original inoculation as a booster.

The decision paves the way for millions more people in the United States to get the additional protection with the highly contagious Delta variant of the virus causing breakthrough infections among some who are fully vaccinated. (Reporting by Ankur Banerjee in Bengaluru; Editing by Bill Berkrot and Leslie Adler)