Two new Omicron sub-variants, BA.4 and BA.5, still have not been detected in Thailand, Ramathibodi Hospital's Centre for Medical Genomics (CMG) says.
The centre wrote in a Facebook post on Tuesday that it was aware of World Health Organization (WHO) concerns over the new Omicron sub-variants which could be more transmittable and cause more severe symptoms.
It said the WHO is now monitoring six Omicron sub-variants: BA.1, BA.1.1, BA.2, BA.3, BA.4 and BA.5.