New COVID-19 Variant XEC: An Emerging Global Concern

A new COVID-19 variant, known as XEC, is spreading quickly and could become the dominant variant worldwide. This variant was initially detected and appears to possess a growth advantage compared to other circulating variants, although it is not drastically different in nature.

XEC is classified as a “recombinant variant,” occurring naturally when an individual is infected with two separate COVID variants simultaneously. It emerged from a genetic recombination between the KS.1.1 variant and the KP.3.3 variant. Both parent variants are closely linked as they evolved from JN.1, which was the dominant variant at the onset of 2024. The XEC variant surfaced in early August 2024 in Germany and other parts of Europe and has since been identified in over 600 cases across 27 countries, including those in Europe, North America, and Asia.

Researchers trace XEC cases using a public database that compiles genetic sequences of viruses for analysis, spotting mutations in SARS-CoV-2, the virus responsible for COVID-19. However, more cases are detected in countries with regular sequencing, leading to higher numbers reported in regions like the United States, Germany, the United Kingdom, Canada, and Denmark.

Despite its rapid spread, XEC is currently a minority variant, with its highest prevalence in Germany. In other parts of Europe and North America, KP.3.1.1 remains dominant, while KP.3.3 leads in Asia. However, XEC’s growth suggests it may become the dominant variant globally in the coming months.

A particular genetic advantage of XEC may include the T22N mutation inherited from KS.1.1 and Q493E mutation from KP.3.3 in the spike protein, which plays a critical role in the virus’s ability to enter human cells. While the impact of the T22N mutation on virulence or transmissibility remains under investigation, it is expected to resemble previous variants in terms of the illness it causes.

No definitive data confirms XEC’s potential impact on health or severity; however, similarities in genetic makeup with previous variants imply it will likely produce familiar symptoms. In the UK, an upcoming autumn booster campaign will introduce an updated vaccine targeting the JN.1 variant to ensure robust protection against severe illness.

XEC is not an entirely new phenomenon, as recombinant variants like the XBB variant dominated in 2023. The emergence of XEC highlights the natural progression and evolution of the virus, necessitating ongoing monitoring. Other variants sharing mutations with XEC, such as MV.1 first reported in India, are also spreading rapidly and warrant close attention.