Overview

Coronavirus continues to evolve swiftly, and a new variant known as XBB1.5 has been rapidly spreading in the U.S. As of January 14, 2023, the CDC estimated it made up 82% of new cases in the Northeast and 43% across the country, making it the most transmissible variant detected to date.¹

Key Facts

• The concern about XB.1.5 is that it is more transmissible and more likely to evade the protection of existing immunity, whether from prior infection, vaccination or both
• XB.1.5 is dominant in the Northeast and mid-Atlantic and is expected to spread rapidly to other parts of the country.
• With the rise of XB.1.5, hospitalizations have increased, although they are still lower than the peak in early winter of 2022.
• Paxlovid appears to be effective against XB.1.5; however, this new strain is resistant to other monoclonal treatments used to treat COVID-19 earlier
  in the pandemic.
• Eligible adults and children are encouraged to receive the Omicron bivalent booster as it is expected to help reduce severe disease and hospitalization due to XBB.1.5 infections.

Sources:
1) https://covid.cdc.gov/covid-data-tracker/#variant-proportions
2) How to Address COVID-19 Vaccine Misinformation | CDC

Population Health Team