'The Kraken' Unleashed: What is Known About 'Most Transmissible' Omicron Offshoot

In the final days of 2022, hospitalizations were notching up across the US, as a new version of omicron gained ground, according to data from the Centers for Disease Control and Prevention. About 40 percent of confirmed US COVID-19 cases were attributed to a subvariant named XBB.1.5.