What we know
Viruses constantly change through mutation, and new variants of a virus are expected to occur over time. Sometimes new variants emerge and disappear. Other times, new variants emerge and persist. Multiple variants of the virus that causes COVID-19 have been documented in the United States and globally during this pandemic.
The virus that causes COVID-19 is a type of coronavirus, a large family of viruses. Coronaviruses are named for the crown-like spikes on their surfaces. Scientists monitor changes in the virus, including changes to the spikes on the surface of the virus. These studies, including genetic analyses of the virus, are helping scientists understand how changes to the virus might affect how it spreads and what happens to people who are infected with it.
Multiple variants of the virus that causes COVID-19 are circulating globally and within the United States. In collaboration with a SARS-CoV-2 Interagency Group (SIG), CDC established 3 classifications for the SARS-CoV-2 variants being monitored: Variant of Interest (VOI), Variant of Concern (VOC), and Variant of High Consequence (VOHC).
There are currently five VOCs in the United States:
B.1.1.7: This variant was first identified in the US in December 2020. It was initially detected in the UK.
B.1.351: This variant was first identified in the US at the end of January 2021. It was initially detected in South Africa in December 2020.
P.1: This variant was first detected in the US in January 2021. P.1 was initially identified in travelers from Brazil, who were tested during routine screening at an airport in Japan, in early January.
B.1.427 and B.1.429: These two variants were first identified in California in February 2021 and were classified as VOCs in March 2021.
Learn more about SARS-CoV-2 Variant Classifications and Definitions.
These variants seem to spread more easily and quickly than other variants, which may lead to more cases of COVID-19. An increase in the number of cases will put more strain on health care resources, lead to more hospitalizations, and potentially more deaths.
So far, studies suggest that antibodies generated through vaccination with currently authorized vaccines recognize these variants. This is being closely investigated and more studies are underway.
Rigorous and increased compliance with public health mitigation strategies, such as vaccination, physical distancing, use of masks, hand hygiene, and isolation and quarantine, is essential to limit the spread of the virus that causes COVID-19 and protect public health.