Sept 23 (Reuters) - A U.S. Centers for Disease Control and Prevention advisory panel on Thursday recommended a booster shot of the Pfizer and BioNTech COVID-19 vaccine for Americans aged 65 and older and some adults with underlying medical conditions.

The vote by the group, following U.S. Food and Drug Administration authorization, clears the way for a booster rollout to begin as soon as this week for millions of people who had their second dose at least six months ago. (Reporting by Manojna Maddipatla in Bengaluru and Michael Erman in New Jersey; Editing by Bill Berkrot)