Omicron sub-lineage designated as variant under investigation in UK

The Omicron variant sub-lineage known as BA.2 has been designated a variant under investigation by the UK Health Security Agency. Overall, the original Omicron lineage, BA.1, is dominant in the UK and the proportion of BA.2 cases is currently low, it said. The designation was made on the basis of increasing numbers of BA.2 sequences identified both domestically and internationally.