What is the Delta variant and where did it come from?
The Delta variant is a highly contagious SARS-CoV-2 virus strain, first identified in India in December 2020. The first Delta case in the United States was diagnosed in March 2021 and it is now the dominant strain in the U.S. This variant seems to spread more easily and quickly than other variants, which may lead to more cases of COVID-19.
Viruses constantly change through mutation, and new variants of a virus are expected to occur. Sometimes new variants emerge and disappear. Other times, new variants persist. Multiple variants of the virus that causes COVID-19 have been documented in the United States and globally during this pandemic.
So far, studies suggest that the current authorized vaccines work on the circulating variants. Scientists will continue to study these and other variants.
Read our Frequently Asked Questions about the COVID-19 Delta Variant
Yes. The Delta variant is now the most common COVID-19 variant in the U.S. and is spreading more easily than other variants. The virus multiplies itself faster, meaning it has a much higher viral load, and is much more contagious.