Currently, Omicron subvariants BA.4 and BA.5 dominate COVID-19 cases in the U.S. Recently, though, another COVID subvariant has gained attention. It's called XBB-or Gryphon-and it could overtake everything else.
As a result of its speedy spread and ability to evade immunity built up by people who have previously been infected or vaccinated against COVID-19, XBB is getting a lot of attention, according to M.D. William Schaffner, an infectious disease specialist and Vanderbilt University School of Medicine professor. "We have a lot to learn," Dr. Schaffner says.
As Amesh A. Adalja, M.D. explains, "XBB is a hybrid of two strains of BA.2 Omicron." In Singapore, it's spreading rapidly. Singapore's Ministry of Health reports that the variant was first detected in India in August 2022, and has since been detected in more than 17 other countries, including Australia, Bangladesh, Denmark, India, Japan, and the United States.
But don't panic. Dr. Adalja emphasizes that vaccine protection is not all or nothing when it comes to evasion. "Vaccine protection against severe disease remains unchanged even with immune-evasive variants.".