Amid warnings from health officials and the White House over a new COVID-19 surge coming this winter, the Centers for Disease Control and Prevention has confirmed a new variant is now dominant in parts of the Northeast. The Omicron subvariant XBB accounts for about 52.6% of all cases in New England between Dec. 18 and Dec. 24, according to the CDC. XBB constitutes 18.3% of cases across the country. “It looks like it’s just going to blow the other (variants) away in a very short period,” Jeremy Luban, professor of molecular medicine, biochemistry, and molecular biotechnology at UMass Chan Medical...