New Covid Variant Is On The Rise

There’s a new coronavirus variant topping the leaderboard in the United States: EG.5.Nationally, EG.5 is causing about 17% of new Covid-19 cases in the country, compared with 16% for the next most common lineage, XBB.1.16, according to the latest estimates from the US Centers for Disease Control and Prevention.EG may sound like a whole new flavor of the virus, but it’s not; it’s a spinoff of the XBB recombinant strain of the Omicron family. And it represents another incremental tweak to the virus rather than a major evolutionary leap like the original Omicron strain.Compared with its parent XBB.1.9.2, it has one extra mutation to its spike, at position 465.

This mutation has appeared in other coronavirus variants before. Scientists aren’t sure exactly what new tricks it enables the virus to do, but variant hunters are paying attention because many of the new XBB descendants have adopted it.The 465 mutation is present in about 35% of coronavirus sequences reported worldwide, including another that’s rising in prevalence in the Northeast, FL.1.5.1, suggesting that it is conveying some kind of evolutionary advantage over previous versions.EG.5 also now has its own offshoot, EG.5.1, that adds a second mutation to the spike.