The new Omicron sub-variant HK.3 has been detected in Thailand for the first time, according to the Department of Medical Sciences (DMS).
Two members of the same family were confirmed to have contacted the new Covid-19 strain, the DMS said but added it could not confirm whether its speed of transmission and severity will be worse than its predecessors.
Department chief, Dr Supakit Sirilak, said the new variant had infected a 65-year-old man and an 11-year-old girl from the same family in Bangkok. They developed mild symptoms and have already recovered, he said.
However, he said it is too early to say if the newly confirmed sub-variant from the Omicron strain will be worse than other sub-variants.
His comments were seen as an attempt to play down fears stemming from a report saying the strain's transmission capacity was 66% faster than current ones and that it might achieve 96% transmission capacity compared with the XBB.1.16 variant found in Thailand.
"There might be some discrepancy in terms of calculation caused by such a limited amount of data. We have found only two confirmed cases. It is too soon to reach such a conclusion. We should wait and see for a couple of weeks for a clearer situation," he said.
Dr Supakit said the department was monitoring Covid-19 sub-variants in the country under a process of whole genome sequencing. This identified sub-variants based on the virus's spike protein mutating in different locations.
Omicron's XBB.1.16 makes up 39.66% of Covid infections in Thailand, followed by XBB.2.3 with 16.39% and XBB.1.9.1 with 14.66%.
He said it is possible that EG.5 will become the dominant variant due to its transmission capacity. However, there was no sign of it being more severe.