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
- About Variants of the Virus that Causes COVID-19 (Centers for Disease Control and Prevention)
- COVID-19 Data Tracker: Variant Proportions (Centers for Disease Control and Prevention)
- 5 Things to Know About the Delta Variant (Yale Medicine)
- Delta variant: 8 things you should know about this COVID-19 strain (UC Davis Health)
- COVID-19 Delta Variant: What Community Members Need to Know (John Hopkins Center for American Indian Health)
Videos
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.