In Region 2 — New York, New Jersey, Puerto Rico, and the Virgin Islands — the spread of the new Omicron sublineage XBB.1.5 is even more pronounced than nationwide. For the week between Dec. 25 and 31, the once-dominant BA.5 is now in fifth place, causing just 1.6 percent of new cases, while XBB.1.5 makes up a whopping 72.2 percent of new cases.