A new Omicron subvariant known as BQ.1.1, first reported in the United Kingdom last month, is now on Thailand's watchlist as the newest fast-spreading coronavirus variant, according to the Center for Medical Genomics at Ramathibodi Hospital.
The centre posted on Facebook that BQ.1.1 has now been reported in 10 other countries, with a total of 78 cases, but not yet in Thailand. It said that twenty-eight new cases were recently recorded by GISAID, the world's Covid-19 database.
According to the centre, the increase in cases in one month means BQ.1.1 could potentially replace BA.5 as the dominant strain.
Its relative growth advantage is approximately 5.3 times greater than BA.5, which makes it the fastest-spreading Omicron subvariant, the centre said, adding that the severity of symptoms is not significantly different from that caused by the BA.5 strain.
Meanwhile, the Ministry of Public Health recommends one or two booster shots against Covid-19 annually after the pandemic ends.
Dr Kiattiphum Wongrajit, the ministry's permanent secretary, said people are now receiving more booster doses, with many receiving a total of five doses.
He said that the Department of Disease Control is now studying to determine the suitable number of boosters people should receive.
He said the ministry currently advises four-month vaccination intervals due to the Covid-19 situation in the country.
He said the vaccine would help improve immunity and fend off the disease.
"Fortunately, right now, the situation has changed," he said. "We have a declining number of daily infections -- the outbreak is now under control."
"So we need to adjust the booster doses in line with the situation," he said.
The ministry recently cancelled many coronavirus-preventive measures, including a vaccine passport programme for all arrivals and the ATK test requirement, after the government deemed the coronavirus situation had improved.
Dr Kiattiphum further said the ministry had adjusted its vaccine purchasing plan, which was initially set at 80 million doses of the vaccine due to arrive next year.
