Cases of the omicron variant of COVID-19 have been discovered in at least 34 states and Washington, D.C., and a new study shows that vaccines are the best protection against it. WATCH THE FULL EPISODE OF 'WORLD NEWS TONIGHT': https://bit.ly/3uHCDO5 WATCH OTHER FULL EPISODES OF WORLD NEWS TONIGHT: http://abc.go.com/shows/world-news-tonight WATCH WORLD NEWS TONIGHT ON HULU: https://bit.ly/3iQLwPp #covid19 #omicronvariant #cdc