The new Covid-19 subvariants Kraken and Orthrus are considered highly transmissible and the Public Health Ministry is urging people with underlying conditions and the elderly to get vaccinated.
Dr Yong Poovorawan, head of the Centre of Excellence in Clinical Virology at Chulalongkorn University, posted on his Facebook page on Wednesday that the two subvariants are adept at circumventing the body's immune system.
People infected recently by the coronavirus are likely to have one of these subvariants, he wrote, with the caveat that Kraken and Orthrus do not present more severe symptoms than other subvariants.
Kraken, or XBB.1.5, was named after the mythical sea monster. It has become the dominant subvariant in the United States and Europe. Meanwhile, Orthrus, or CH.1.1, named after the two-headed dog in Greek mythology, has spread widely in the US.
Dr Yong said Kraken can resist immune responses and is prone to mutate in the future.
The two subvariants are descendants of Omicron or the BA.2 variant, he said.
Only a small number of Covid-19 cases in Thailand are showing the new subvariants, with the Centre of Excellence in Clinical Virology finding just five cases in December and January, all imported from foreign countries, he added.
There are 36 Covid-19 inpatients per day on average and four deaths a week, according to the Department of Disease Control. Some 122 patients have developed lung infections and 78 need oxygen supplements.
