The Centre for Medical Genomics at Ramathibodi Hospital expects the number of COVID-19 infections to start dropping towards the end of this month.
Dr Wasun Chantratita, head of the centre, said the current surge in COVID-19 cases in Thailand, especially Bangkok, is expected to involve the Omicron BA.2 subvariant which is more transmissible than the BA.1 subvariant.
Citing the spread of the Omicron variant in other countries, he said the number of COVID-19 cases in the kingdom is likely to start to decline around the end of this month.
Dr Chantratita said the centre examined a total of 192 samples collected in Bangkok and surrounding provinces in January and this month and found that 88% were the BA.1 subvariant, 5% were BA.1.1 and 1% were BA.2.
Gisaid, the global data science initiative, reported that 60% of cases were the BA.1.1 subvariant, 19% were BA.1 and 2% were BA.2.
Dr Chantratita said the number of BA.2 subvariant cases is believed to have increased due to its high transmissibility, but the subvariant is not more virulent than the original Omicron variant.
While Thailand has seen an increase in infections, the death rate was low as a result of high vaccination rates and proactive screening which is taking place in communities, he added.