The Delta Variant

Information and resources related to the spread of the Delta variant in the U.S.

What is the Delta variant?

Viruses mutate and evolve over time, forming variants that sometimes spread more easily or become resistant to treatments and vaccines. Scientists are currently monitoring multiple variants of SARS-CoV2, the virus that causes COVID-19. One such variant, the Delta variant (B.1.617.2), is a highly contagious strain of the virus that was first identified in India in December of 2020 and was detected in the U.S. in March 2021 (source: CDC). As of late July 2021, Delta is responsible for more than 80 percent of COVID-19 cases in the U.S. (Source: CDC.)



Information and Resources


The COVID-19 Delta Variant Explained

Dr. Lorena Garcia, professor of epidemiology at UC Davis School of Medicine, explains how the COVID-19 Delta variant is different, what you can do to stay safe and how vaccines could make a difference in preventing future COVID-19 variants.