The data on this page show how variants of the virus that causes COVID-19 are spreading in NYC. Variants are versions of the virus with certain sets of mutations. Some variants may result in a COVID-19 infection that is easier to spread, more severe or able to avoid antibodies from vaccines or previous infections.
There are not enough data to draw firm conclusions yet about some of the properties of these variants. The Health Department will continue to investigate whether they are more likely to cause reinfections, increase disease severity or reduce the immunity from vaccine or previous infection.
The CDC classifies some variants as:
The table below shows variants that have been observed in New York City and their classification. Currently, B.1.1.7 (alpha) and B.1.617.2 (delta) are the most widespread variants in the city. We are also closely monitoring P.1 (gamma) and B.1.526 (iota), which have been spreading rapidly in the U.S. and other countries.
Note: To help with reference, the World Health Organization (WHO) has assigned Greek letters to variants, such as: alpha (B.1.1.7), iota (B.1.526), gamma (P.1) and delta (B.1.617.2).
These charts show the percent of NYC's confirmed COVID-19 cases that have been tested for virus variants and reported to the Health Department, and the total number tested each week.
These charts show the percent and number of tested cases each week that have the four most common variants in New York City: B.1.1.7, B.1.526, P.1 and B.1.617.2.
New York City’s Public Health Laboratory, Pandemic Response Laboratory, and hospital and private laboratories have been testing COVID-19 cases to identify emerging variants of the virus.
Cases are tested for variants only if they meet certain criteria, such as having enough virus in the sample. However, these findings are still reliable, as the tested cases generally reflect all cases in NYC.