The faster spreading BA.2 subvariant of Covid-19's Omicron variant accounted for 18.5% of Omicron cases examined over the past week, the Department of Medical Sciences reported.
Director-general Supakit Sirilak said on Tuesday that the department examined 567 Omicron cases from Feb 5 to 11 and found 18.5% were of the BA.2 subvariant and the rest BA.1.
"There are some signs that BA.2 spreads faster than BA.1 looking at cases in other countries but there has not been any significant difference from BA.1 when it comes to severity and vaccine avoidance," Dr Supakit said.
The department also found BA.2 in 19% of 42 imported Omicron cases sampled for examination over the same period.
According to the director-general, BA.2 has been detected in 57 countries and is likely to replace BA.1 in India, Denmark and Sweden. BA.2 has already superseded BA.1 in Denmark and could replace BA.1 in Thailand given its faster spread.
BA.2 was first recorded in Thailand among visitors early this year. Today there are rare cases of other variants of Covid-19 in the country.
Omicron is already a dominant variant of Covid-19 worldwide and booster vaccine shots could prevent infection, severe illness and fatalities caused by BA.2 according to overseas papers.
From Jan 30 to Feb 4, Omicron cases formed 94.2% of Covid-19 cases in Thailand and Delta the rest, 5.8%. Omicron was found in 99.4% of infected arrivals over the same period.
Bangkok had the largest number of accumulated Omicron infections with 6,641 cases including 2,132 local infections, followed by 1,286 cases in Phuket, 1,240 in Chon Buri, 670 cases in Roi Et, 590 in Samut Prakan, 534 in Nong Khai, 511 in Surat Thani, 508 in Maha Sarakham, 419 in Kalasin and 410 in Khon Kaen.
