A new COVID-19 Omicron sub-variant known as BA.2 has been detected in the United States, officials said, coming after officials in the United Kindom and Denmark published reports on the strain in recent days. “There is still uncertainty around the significance of the changes to the viral genome, and further analyses will now be undertaken,” the UK Health Security Agency said in a news release. UK researchers said an early analysis suggests BA.2 is more transmissible than the first Omicron strain, which was named as a “variant of concern” by the World Health Organization in November. However, the team said that they have not been able to find a meaningful difference between the original strain and BA.2. There have been about 400 confirmed BA.2 cases in 40 countries. The first was confirmed in December, the UK agency said. “So far, there is insufficient evidence to determine whether BA.2 causes more severe …