The Centre for Medical Genomics (CMG) at Ramathibodi Hospital has predicted the more transmissible BA.4 and BA.5 Omicron subvariants are likely to become dominant strains in Thailand next month.
Dr Wasun Chantratita, who heads the centre, said 11 cases of BA.4 and 18 cases of BA.5 were detected in the kingdom between June 7 and 24.
The number of cases corresponds with global trends, with the subvariants expected to take over as the dominant strains in the world, he said.
"The BA.4 and BA.5 Omicron subvariants are also expected to be the dominant strain in Thailand from late next month or early September," he said.
Citing data from Gisaid, the global data science initiative, he said new BA.4/BA.5 cases have surged in Europe. Previously, Portugal saw an alarming surge in BA.4/BA.5 cases before infections declined, he said.
If the subvariants pose any major concern, the World Health Organization will have to call for an urgent meeting to discuss ways to deal with the issue, he said.
No significant data regarding the genome sequencing of the two Omicron subvariants has been uploaded on Gisaid's website yet, he said.
Dr Supakit Sirilak, director-general of the Department of Medical Sciences, said more details regarding the Omicron subvariants will be published tomorrow.
Currently, the department is conducting a weekly analysis of the subvariants to determine the speed of transmission, he said, adding the department will also need more time to study the severity of illnesses caused by the subvariants.
Several hospitals have been asked to send samples from patients infected with the subvariants to the department for analysis, Dr Supakit said.
Meanwhile, Rachada Dhnadirek, a deputy government spokeswoman, said Covid-19 patients with mild symptoms can still access free outpatient treatments at hospitals where their state welfare and/or health insurance scheme is registered, even if the pandemic is declared an endemic.
The Centre for Covid-19 Situation Administration (CCSA) has postponed downgrading Covid-19 to an endemic disease on Friday to a later date following a rise in infections of BA.4 and BA.5 subvariants.
"Prime Minister Prayut Chan-o-cha has emphasised the need to look after people of all groups... If they are infected with Covid-19, they can still receive medical treatment free of charge under the welfare schemes they are entitled to," Ms Rachada said.