11 July 2024

The rapid spread of COVID-19’s latest subvariant – XBB – is grabbing attention worldwide, including in Thailand.

Three weeks after it was first detected in Singapore, XBB now accounts for at least half of the island state’s new cases. Thailand decided to step up its monitoring for the subvariant not only because Singapore is a neighbor but also because three XBB cases recently detected in Hong Kong had flown in from Thailand.

Under focus

The World Health Organization (WHO) has listed XBB as an Omicron subvariant under monitoring, indicating it may pose a new threat to global public health. First detected in August, the new subvariant is a recombinant of Omicron’s BA.2.10.1 and BA.2.75 sub-lineages or BJ1 and BM.1.1.1.

So far, XBB infections have been found in more than 17 countries, including Australia, Bangladesh, Denmark, India, Japan and the United States. While there is no evidence that XBB causes more severe symptoms than previous versions of the virus, some experts suggest it may be more transmissible than other strains.

“XBB has become the dominant strain in Singapore, demonstrating that it can outrun and outdo other strains,” infectious disease expert Dr. Leong Hoe Nam of Singapore’s Rophi Clinic was quoted as saying by an Indian news outlet.

Some experts add that XBB appears to be better at evading vaccines than previous COVID versions.

Assoc Prof Thira Woratanarat, a lecturer at Chulalongkorn University’s Faculty of Medicine, said reports from Singapore suggest that people who have never caught COVID-19 or have been infected by pre-Omicron variants are at higher risk of contracting XBB.

“But even among those who have caught Omicron, their infection risk is significantly higher after three months,” he added.

Threat to Thailand

No XBB cases had been reported on Thai soil as of press time. As such, Medical Sciences Department (MSD) director-general Dr Supakit Sirilak is urging people not to panic over XBB.

“We are conducting random tests on people arriving from countries where the subvariant has spread, especially Singapore,” said Supakit, insisting that Thailand’s COVID-19 monitoring system remains strong. He added that Omicron BA.5 remains the dominant subvariant in Thailand.

Dr Tares Krassanairawiwong, director-general of the Disease Control Department, said authorities were seeking the identity and travel histories of the three XBB cases from Thailand detected in Hong Kong.

The changing symptoms associated with COVID-19 infection

Advice for Thais

Health authorities meanwhile are urging Thais to keep their guard up against COVID-19 despite its reduction in status from a dangerous communicable disease to a monitored communicable disease.

People are advised to continue wearing face masks, maintain social distancing, wash their hands frequently, and get their booster shots.

Public Health Ministry permanent-secretary Dr Opart Karnkawinpong said campaigns to urge people to get vaccinated would continue. On October 12, the government began offering COVID-19 jabs for toddlers aged six months to four years old.

“We also strongly recommend that people with health risks, including the elderly and the obese, get their booster shots,” he said.

While COVID-19 jabs do not prevent infection, they significantly reduce the risk of hospitalization and severe symptoms or death.

Dr Nakorn Premsri, National Vaccine Institute director, said COVID-19 continues to kill and make people severely ill – especially those who are either unvaccinated or only partially vaccinated.

In Thailand, 58 people died of the virus in the week from October 2-8 alone, while 225 patients were on ventilators as of October 8.

“Please stop waiting for the next-generation, or any specific vaccine to arrive. Go and get your shots as recommended,” Nakorn said, replying to questions about bivalent vaccines that are being used in the US and Europe but have yet to reach Thailand.

Bivalent vaccines, also known as “updated boosters”, immunize recipients with two mRNA components of the COVID-19 virus – one of the original strain and another that covers the BA.4 and BA.5 lineages of Omicron.