The World Health Organisation (WHO) said that two more new Omicron sub-variants – BA.4 and BA.5 – are now under the radar of the agency. A Reuters report quoting WHO’s official communication wrote that the UN health agency has added BA.4 and BA.5, sister variants of the original BA.1 Omicron variant, to its list for monitoring. It is already tracking BA.1 and BA.2 – now globally dominant – as well as BA.1.1 and BA.3.