New COVID-19 Variant “XFG” Spreads Fast but Causes Mild Symptoms, Says Department of Medical Sciences

The Department of Medical Sciences has reported the emergence of the new COVID-19 variant XFG, which spreads rapidly but is not considered severe. The department reassured the public that Thailand’s disease surveillance system remains robust and urged people to continue practicing self-protection through mask-wearing and frequent handwashing.

On October 7, 2025, SARAWUT BOONSUK, MD. Director-General of the Department of Medical Sciences, stated that ongoing surveillance of COVID-19 continues, particularly focusing on the new XFG variant, also known as “Stratus.”
The World Health Organization (WHO) classified this strain as a Variant Under Monitoring (VUM) in June 2025. XFG is a sublineage of Omicron, featuring multiple spike protein mutations that allow for faster transmission and potential immune evasion. However, current data confirms that there is no evidence suggesting increased disease severity.

In Thailand, the first case of the XFG variant was detected in April 2025. Between April 1 and October 4, 2025, a total of 34 cases have been identified—most with mild symptoms such as fever, cough, sore throat, and runny nose.

SARAWUT , MD further explained that between April 1 and October 4, 2025, the department conducted genomic sequencing of 613 COVID-19 samples to monitor ongoing mutations. The results showed the following distribution:

   - NB.1.8.1* – 73.4%

   - XEC* – 8.6%

   - JN.1* – 6.5%

   - XFG* – 5.5%

   - Other variants – 5.9%

He added that Thailand has shared over 48,870 viral genome sequences to the global GISAID database since the beginning of the pandemic, demonstrating the strength and capability of the country’s laboratory network.

“The detection of the XFG variant highlights Thailand’s strong and ongoing disease surveillance system. The Department of Medical Sciences remains proactive—not only to control outbreaks but also to strengthen national health security and support the country’s health economy,”
said Dr. Sarawut.

The department reassured the public that although XFG spreads faster, it does not cause severe illness. People are advised to continue preventive measures, including wearing masks in crowded areas, washing hands regularly, and using ATK tests if symptoms develop.

 

Source:

www.thaihealth.or.th