The newest Omicron variant, BA.4/5, is gaining traction, causing case, hospitalization, and death curves to trend upwards in many countries. This variant was first detected in South Africa in early 2022.

“The BA.4/5 impact is just starting to take hold, with no region of the U.S. at a dominant level yet,” Dr. Eric Topol, a professor of molecular medicine at Scripps Research and founder and director of the Scripps Research Translational Institute, tweeted Tuesday.

BA.4 and BA.5 were first detected in the U.S. in late March.