The Centers for Disease Control and Prevention (CDC) reports an increase in COVID-19 infections throughout the nation. Most recently, XBB.1.5, a new Omicron subvariant of significant concern, has surged to represent 40.5 percent of all United States COVID-19 cases. This variant is noted to be highly transmissible. As of Dec. 13, 75.3 percent of Massachusetts COVID-19 cases were estimated to be the XBB.1.5 variant.