The Department of Medical Sciences (DMS) has found two cases of a new sub-variant of Omicron, XBB.1.5, which has a strong transmission capacity.
Dr Supakit Sirilak, the DMS chief, said the department recently detected XBB.1.5 -- also known as Kraken -- in a Thai national and a foreigner.
They have both since recovered, and none of their family or close friends have been infected, he said.
Named after the mythical sea monster, it is classified as a new sub-variant due to its mutations, which makes it easier to attach itself to human cells and evade antibodies.
Despite the faster rate of transmission, however, there is no solid evidence showing that XBB.1.5 will cause more severe symptoms that other sub-variants, Dr Supakit said.
He said it is a combination of Omicron's two sub-variant BA.2 strains, namely BJ.1 and BM.1.1.1.
XBB.1.5 has become the dominant sub-variant in the United States and Europe.
From last October to Feb 1, there were 33,219 XBB.1.5 cases reported worldwide, with 73.7% of them recorded in the United States, 6.6% in the UK, 5.3% in Canada, 2.65% in Germany, 1.5% in Austria, 1% in Denmark and 1% in Ireland.
In Thailand, BN.1, which is a descendant of BA.2.75, is the dominant sub-variant, Dr Supakit said, adding the department has monitored the mutations and severity of symptoms to set up a suitable policy to control infections in the future.
At the present time, basic Covid-19 protection measures such as regular hand washing, wearing a face mask and getting vaccinated are still the best preventive measures to combat the disease, he added.
