Thailand detects FU.1 Covid sub-variant, 50% more transmissible than XBB.1.16

Thailand’s Centre for Medical Genomics has reported a single case of the Covid-19 sub-variant known as “FU.1” or XBB.1.16.1.1, which is said to be 50% more transmissible than XBB.1.16. The Omicron variant continues to mutate into new sub-variants, despite a decrease in global Covid cases.

Currently, the dominant Omicron sub-variants are XBB.1.5, XBB.1.16, and XBB.1.9.1. The Centre for Medical Genomics at Ramathibodi Hospital revealed that XBB.1.16 and XBB.1.9.1 have become the dominant strains worldwide, including in Singapore and Thailand. The centre analysed genomic codes from Thai Covid patients and the global genomic database Gisaid between April 15 and May 15.

The results showed that 93.5% of Omicron cases in Thailand were of the XBB sub-variant, with 19% being XBB.1.16, 10% XBB.1.5, and 8.4% XBB.1.9.1.

Globally, XBB.1.16 was identified in 9,003 Covid cases, with 139 cases in Thailand. Its sub-lineage, XBB.1.16.1, was found in 2,714 cases worldwide and 26 cases in Thailand. XBB.1.16.2 was detected in 666 cases globally and 25 in Thailand, reported Bangkok Post.

XBB.1.16.3 was found in 175 cases worldwide, with five cases in Thailand.

The FU.1 sub-variant, which is more widespread in Shanghai, has infected 122 people globally. The FU.2 sub-variant has been identified in 149 cases worldwide. In Thailand, only one case of FU.1 has been detected, with no cases of FU.2 reported. According to the centre, FU.1 is 50% more transmissible than XBB.1.16.

The centre predicts that the Omicron sub-lineages XBB.1.9.1 and FL will become more widespread and will be the dominant sub-variants in the future.