14 now infected with Omicron ‘stealth’ subvariant, one dies
Fourteen patients in Thailand have been infected with Covid-19 Omicron subvariant BA.2, with one dying, Department of Medical Sciences director-general Dr Supphakit Siriluck reported on Wednesday.
Omicron BA.2 has been nicknamed the “stealth variant” due to difficulties in comparison between this particular variant and Delta using the RT-PCR method.
BA.2 is spreading rapidly in around 40 countries, including Singapore, India, Denmark, Sweden and the UK.
“The Omicron variant that has been found in Thailand since December 6 last year is the BA.1 variant that has mutations in the K417N, T478K, N501Y and del69/70 positions from the original Covid-19 virus,” Supphakit explained.
“About three weeks after it was first discovered among foreign travellers, the BA.1 variant has spread quickly throughout a number of countries with several clusters reported in populated and tourism areas,” he said.
“The Omicron BA.2 subvariant was first found in Thailand on January 2. Since then, 14 patients have been reported to have contracted it,” Supphakit said, adding that Omicron BA.3 “has yet to be discovered in Thailand”.
Supphakit said that so far there was no evidence BA.2 was different from BA.1 in terms of transmissibility, the potential for a patient to develop severe symptoms, or the ability to evade immunity created after recovering from Covid-19 or by receiving a vaccine.
“Apart from being hard to differentiate from Delta variants with RT-PCR testing, the BA.2 subvariant is different from BA.1 and BA.3, meaning that it does not show any mutation in the positions 69-70 of the spike protein,” he added.
So far, seven patients in Thailand infected with the Omicron variant have died, bringing the fatality rate of Omicron in the country to 0.1 per cent. Omicron is now the dominant variant in Thailand, accounting for 94.6 per cent of patients. For Delta it is 5.4 per cent.
When divided by origin, 99.4 per cent of imported cases are of the Omicron variant while 0.6 per cent is Delta. Currently, 92.3 per cent of domestic cases are Omicron and 7.7 per cent Delta.
