Omicron BA.2 is the new version of the Omicron variant of COVID-19. It is also being widely considered stealthier than the original version of Omicron.
source https://www.jagranjosh.com/current-affairs/top-10-weekly-current-affairs-upsc-ssc-govt-jobs-24-january-to-29-january-2022-1643377446-1