The new omicron subvariant XBB.1.5 is seeing a “stunning” rate of increase . . . and is on track to become the dominant strain circulating across the country, prompting many public health officials to voice concerns about the highly transmissible strain. https://www.usnews.com/news/health-news/articles/2023-01-06/explainer-what-to-know-about-new-omicron-subvariant-xbb-1-5