US CDC concerned for new Omicron subvariants

The US Centers for Disease Control and Prevention (CDC) is closely tracking a wide range of Omicron sublineages, including three drawing recent attention, the agency said on Friday.

The three new subvariants are BQ.1, BQ.1.1 and XBB. BQ.1 and BQ.1.1 are offshoots of the BA.5 subvariant, which has been dominant in the United States for months, according to the CDC.

CDC data show that BQ.1 and BQ.1.1 seem to be spreading relatively quickly so far, but they are still a small proportion of overall variants.

The CDC is also keeping a close eye on XBB based on international reports, although it is still very rare in the United States.

Numerous variants of SARS-CoV-2, the virus that causes COVID-19, have been tracked in the United States and globally during the pandemic.

Sometimes new variants emerge and disappear. Other times, they persist and continue to circulate in communities. As the virus spreads, it has new opportunities to change in ways that can make emerging variants more difficult to stop because the effectiveness of vaccinations or treatments may be reduced, according to the CDC.