A new COVID XEC variant is spreading rapidly

A new COVID variant is spreading rapidly and could soon become the dominant variant around the globe. The variant, called XEC, was first detected in Germany in August and appears to have a growth advantage over other circulating variants – but it is not a radically different variant.

XEC is what’s known as a “recombinant variant”. Recombinants can occur naturally when a person is simultaneously infected with two different COVID variants.

XEC is the product of a recombination (exchanged pieces of genetic material between two variants) between the KS.1.1 variant and the KP.3.3 variant. These two parent variants are closely related, having both evolved from JN.1, which was the dominant variant around the world at the start of 2024.

XEC was first reported in early August 2024 in Germany and a few other European countries but has since continued to spread, with over 600 cases identified in 27 countries across Europe, North America and Asia.

Scientists identify XEC cases using a public database called Gisaid, to which genetic sequences of viruses are uploaded for analysis. It is here that mutations in SARS-CoV-2 are spotted (SARS-CoV-2 being the virus that causes COVID).

But it’s a bit like a drunk looking for his lost keys under the street lamp because that’s where the light is best. In other words, more cases of new variants are spotted in those countries that typically sequence more COVID samples through routine surveillance programmes.

（華盛頓23日綜合電）美國近期天氣轉涼，讓今夏的新冠疫情稍微緩和，然而專家警告，一種新的COVID-19變種病毒正在歐洲擴散，美國與中國已經出現多起病例。

新變種病毒XEC和MV-1正在多國悄然蔓延，雖然世界衛生組織（WHO）尚未正式公佈XEC的相關資訊，但追蹤COVID-19疫情的Outbreak.info平台已經掌握該病毒的基因定序，並認為這個變種病毒很可能會引發下一波全球大流行。

范德比大學（Vanderbilt University）醫學院教授夏夫納（William Schaffner）指出，XEC是新的COVID-19變種，目前全球正密切關注此病毒，“它屬於Omicron變種之一，並且看似具有一定的傳染力”。

據資料顯示，XEC是Omicron亞變種KS.1.1和KP.3.3的混合體，而KP.3.3則是KP.3的分支，也是今夏流行的病毒株之一。

專家表示，XEC比上述病毒毒性更強，症狀與以往的變種病毒相似，包括發燒、發冷、咳嗽、疲倦、頭痛、肌肉酸痛、喉嚨痛及腹瀉等。

目前，XEC病毒主要在歐洲流行，已經在波蘭、挪威、盧森堡、烏克蘭及葡萄牙出現，也在中國現蹤。美國目前已知有23宗確診病例，其中3宗來自加州。

夏夫納建議，在旅行或擁擠的室內場所佩戴口罩，這有助於降低感染風險。儘管目前尚無針對新病毒株的專門疫苗，但10月是接種疫苗的好時機，有望提供整個冬季的保護力。