
The World Health Organization (WHO) has issued a warning over the emergence of three Omicron sub-variants that have the potential to transmit Covid-19 faster and infect the lungs, says the Ramathibodi Hospital's Center for Medical Genomics (CMG).
Sub-variants BA.4, BA.5 and BA.2.12.1 may cause more severe infections than the Omicron strain, it said on its Facebook page.