A new COVID-19 variant called LB.1 is contributing to a recent rise in infections across the United States, the U.S. Centers for Disease Control and Prevention (CDC) said in a post on Friday.

COVID-19 test positivity in the U.S. has increased to 6.6 percent from 5.4 percent in the previous week.

Data from the CDC shows that currently, LB.1 is the third dominant variant in the U.S., accounting for 17.5 percent of the cases from June, following KP.3 and KP.2 with 33.1 percent and 20.8 percent of cases, respectively.

All three of these variants share a common ancestor in the JN.1 strain that drove a wave of cases last winter. Both LB.1 and KP.3 are being monitored by the CDC as they are becoming widespread across the country.