Multiple variants of the virus that causes COVID-19 have been documented in the United States and globally during this pandemic. There are currently four notable variants in the United States:
B.1.1.7 (Alpha): This variant was first detected in the United States in December 2020. It was initially detected in the United Kingdom.
B.1.351 (Beta): This variant was first detected in the United States at the end of January 2021. It was initially detected in South Africa in December 2020.
P.1 (Gamma): This variant was first detected in the United States in January 2021. It was initially identified in travelers from Brazil, who were tested during routine screening at an airport in Japan, in early January.
B.1.617.2 (Delta): This variant was first detected in the United States in March 2021. It was initially identified in India in December 2020. Based on current data, this is a common variant across the country. There remain small areas of the country where Delta variant is prevalent. Vaccination still seems to be effective against the different variants. It’s important to continue to follow public health recommendations, including vaccination, physical distancing, use of masks, hand hygiene, and isolation and quarantine, as appropriate, to limit the spread of COVID-19.
B.1.1.529 (Omicron): This variant was first detected in the United States in December 2021. It was initially identified in South Africa in November 2021. Omicron remains the predominant strain in the United States. There is evidence that this and other variants spread more easily than other COVID-19 strains, and Omicron has been classified as a Variant of Concern by the World Health Organization (WHO).Vaccination still seems to be effective against the different variants. It’s important to continue to follow public health recommendations, including vaccination, physical distancing, use of masks, hand hygiene, and isolation and quarantine, as appropriate, to limit the spread of COVID-19.
