The Department of Medical Sciences has announced the identification of the “XFG” variant of COVID-19,a species designated as a “Variant Under Monitoring” by the World health Organization (WHO). This designation stems from its rapid spread and enhanced ability to evade immunity, although current evidence does not indicate more severe illness compared to other strains.

Dr. Yongyot Thamwut,Director-General of the Department of Medical Sciences,revealed that the WHO’s announcement on June 25,2025,highlighted XFG as a variant of concern due to these characteristics. XFG is an Omicron sub-variant, formed by the combination of the LF.7 and LP.8.1.2 strains. It was first detected on January 27, 2025, and possesses eleven additional mutations in its Spike Protein, including T22N, K182R, R190S, K444, V445R, N487D, Q493E, and T573E. These mutations are believed to contribute to its increased transmissibility and immune evasion.

Globally, the XFG variant is projected to see a continuous increase, while the NB.1.8.1 strain remains the most prevalent, albeit with a declining trend.In Thailand, the first detection of XFG occurred in April 2025, with 23 reports to date. The Department of Medical Sciences is actively sequencing viral infections to monitor mutations. Between May 26 and June 23,2025,236 genetic codes were analyzed,revealing NB.1.8.1* at 83.9%, XFG* at 6.8%, XEC* at 5.9%, and other variants like JN.1* and LP.8.1* in smaller proportions.

The Department of Medical sciences remains committed to monitoring viral strain changes and regularly submits genomic data to the Gisaid international database to support global disease surveillance. As the initial outbreak in Thailand in January 2020, the country has contributed a total of 48,541 COVID-19 genomes.

While there is no current confirmation of XFG causing more severe symptoms, the public is urged to continue adhering to preventive measures. These include frequent hand washing, avoiding crowded places, and seeking medical attention if experiencing symptoms such as fever, cough, or difficulty breathing for proper diagnosis and treatment.