COVID Variants

What are COVID variants and how do they occur?

COVID variants are versions of the COVID virus that can be distinguished by differences (or variations) in their genetic code.

The formation of COVID variants was not unexpected. Changes in a virus’s genetic code (mutations) happen continuously as a virus replicates. The more a virus spreads, the more chances it has to replicate and mutate. So, genetic variations occur over time, and if certain variations make a virus better able to infect more people (like Delta or Omicron), it will come to predominate (be more common).

More information about variants can be found at:

How are COVID variants distinguished from one another?

COVID variants are distinguished from one another by a laboratory process called genomic sequencing. Genomic sequencing involves making a map of the entire genetic code of the virus. The process takes several days and is only done in specialized labs with this capability.

Do standard COVID tests tell us what variant a person is infected with?

No, standard COVID tests tell us if the COVID-19 virus is detected in the sample, but they do not distinguish between variants of the virus–that requires genomic sequencing.

Is genomic sequencing done for every positive COVID test?

No, genomic sequencing is only done on some positive samples for the purpose of genomic surveillance.

What is genomic surveillance and why is it important?

The goal of genomic surveillance is to continuously sequence enough positive samples across all areas of the state and the country to allow us to see what variants are circulating in what proportions where. Genomic surveillance allows scientists to monitor how the virus changes into new variants over time, study how mutations may affect the characteristics of the virus, and use this information to better understand how it might impact health.

More information about how variants are tracked in New York State can be found at:

How can I find out what variants are circulating in my area?

The New York State Department of Health (NYSDOH) provides a summary of variants currently circulating in NY, as well as charts displaying proportions of variants over time for NY and CDC Region 2 (includes NY) at:

Why are variants a concern?

Not all variants are a concern, but some mutations might make a new variant more contagious, result in more severe illness, or reduce the effectiveness of vaccines and treatments. Scientists analyze the mutations observed in a new variant to determine if they are of concern.

Do vaccines work against variants?

National data are showing that COVID-19 vaccines authorized in the USA are highly effective in preventing severe disease and death, even against variants. However, we are seeing increases in the risk of becoming infected for vaccinated people.

How has the spread of variants changed public health recommendations?

Given what we have learned about variants, and trends in virus transmission, public health professionals are recommending layered protection strategies to reduce transmission of this variant. Layered prevention strategies include continuing to increase primary series and booster vaccination rates, but also continued attention to tried and true prevention strategies like masking, social distancing, and handwashing.

So, does that mean if I am vaccinated, should I still wear my mask?

There are definite benefits for vaccinated individuals to wear a mask in certain situations. The Centers for Disease Control (CDC) has made the following updates to its guidance for those vaccinated individuals: This information is subject to change.

Last reviewed: August 2, 2022