A new SARS-CoV-2 omicron subvariant, XBB.1.16, is spreading throughout several countries, including parts of the U.S. Health officials at the World Health Organization have said it is something they are closely monitoring.
While XBB. 1.16 has similarities to the current dominant strain in the U.S., XBB.1.5, Maria Van Kerkhove, PhD, the WHO's technical lead for COVID-19, noted in a March 29 media briefing that in lab studies the new subvariant has demonstrated qualities that show "increased infectivity" and "potentially increased pathogenicity." However, at this time, Dr. Van Kerkhove also says they "haven't seen a change in severity in individuals or in populations."
Here are 11 things we know about XBB.1.16 to date:
- The omicron subvariant has been in circulation for a few months.
- The main difference between XBB.1.16 and XBB.1.5 is a change in the spike protein.
- Cases caused by the new subvariant have been identified in 18 states and counting.
- Southeast Asia and the Middle East are currently the regions that have seen the most cases of the new subvariant.
- XBB.1.16 has replaced other variants and is now the dominant strain in India.
- In total, the WHO said in its press conference there are currently 800 sequences of XBB.1.16 from 22 countries.
- The WHO officially added XBB.1.16 to its list of variants to monitor as of March 22.
- XBB.1.16 is not yet part of the CDC's variant proportion tracker.
- At this time, cases of XBB.1.16 are being tracked in a public database created by Raj Rajnarayanan, PhD, an assistant dean of research and associate professor at Arkansas State University in Jonesboro.
- A descendant of the new subvariant — XBB.1.16.1 — has been spotted in at least 18 states, according to the tracker.
- The subvariant is also being referred to by the name "Arcturus," but it's not an official name from the WHO.