Dr. Anthony Fauci said the delta variant is currently “the greatest threat in the U.S.” in the fight against COVID-19. Officials warn that younger people could be more vulnerable to the variant. WATCH FULL EPISODES OF WORLD NEWS TONIGHT: https://abc.com/shows/world-news-tonight WATCH WORLD NEWS TONIGHT ON HULU: https://bit.ly/3iQLwPp #WorldNewsTonight #DrAnthonyFaci #COVID-19 #DeltaVariant #Vulnerable