COVID-19 variant trackers are now closely watching the rise of a new virus variant called XEC, which has been spotted around the world and in half of states across the United States. Health officials are so far not raising concern about this variant, unlike some previous, more highly mutated strains that worried experts.

Currently available COVID vaccines target slightly different subvariants. The updated mRNA shots aimed at KP.2 from Pfizer-BioNTech (Comirnaty) and Moderna (Spikevax), as well as Novavax's vaccine targeting the JN.1 variant lineage, are still protective against the most serious consequences of COVID infections, experts said.

COVID XEC variant has been confirmed in 27 countries in Europe, North America and Asia, according to data specialist Mike Honey, as the strain grows.