37, was first identified in Peru as early as August 2020. Initially, Lambda infections were relatively rare. However, in recent months Lambda has become the dominant variant in Argentina, Chile, and Colombia. Lambda has been identified in most US States, though the strain has yet to gain traction.

Is the Mu variant of COVID-19 in the United States?

Fauci said at a press conference that the prevalence of the mu variant is "extremely low" in the U.S., with it making up 0.5% of new cases.

What is the predominant strain of COVID-19 in the U.S.?

The highly transmissible B.1.617.2 (Delta) variant of SARS-CoV-2 has become the predominant circulating U.S. strain.