Variants of the Virus that Causes COVID-19

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Variants of COVID-19

Variants of COVID-19

Multiple variants of the virus that causes COVID-19 have been identified globally and in the United States, including Virginia. Getting vaccinated  [Español ] is the most important step you can take to protect yourself and others from COVID-19 variants.

Top Things You Should Know about Variants

  1. The Omicron variant has quickly become the dominant variant of concern in the United States. Omicron spreads more easily than the original SARS-CoV-2 virus and data suggest that the Omicron variant is up to three times more infectious than the Delta variant.
  2. People who have previously had COVID-19 could become re-infected more easily with Omicron compared to other variants of concern. Staying up to date on vaccinations provides the best protection from Omicron.
  3. Being up-to-date with COVID-19 vaccines provides the BEST protection against the illness that we currently have.
  4. COVID-19 vaccines [Español ] available in the United States are safe and effective at protecting people from severe illness, hospitalization and death from circulating variants of the COVID-19 virus. Boosters are now recommended to maintain a high level of protection.
  5. The more the COVID-19 virus circulates, the greater the chances that new mutations or variants can develop. The best way to slow the emergence of new variants is to follow public health recommendations  shown to reduce the spread of COVID-19. Keep yourself and others safer by:
  • Getting a complete COVID-19 vaccine series, including any recommended booster dose(s). All people aged 5 years and older are eligible for a primary COVID-19 vaccine series and it is strongly recommended that you receive this. Find your free COVID-19 vaccine and learn more at [Español ] or call 877-VAX-IN-VA (877-829-4682).
  • Choosing to wear a mask that covers your nose and mouth when you are around people who do not live in your household and wearing a mask indoors in public if you are in an area with a high COVID-19 community level.
  • Staying at least 6 feet apart from other people when possible.
  • Keeping away from large crowds and poorly ventilated spaces.
  • Washing your hands often.
  • Delaying travel if you are not up-to-date on your COVID-19 vaccination.

Table of Contents

About Viruses

COVID-19 is caused by a virus known as SARS-CoV-2, which stands for Severe Acute Respiratory Syndrome Coronavirus 2. Viruses cannot survive and produce more viral copies (replicate) on their own. They survive by entering the body of a person or animal that is able to be infected. After a person is exposed to the virus, the virus enters the person’s cells. Once inside the cells, the virus takes over the cell’s machinery to produce more copies of the virus. This process of making new copies of a virus within a cell is called viral replication. 

As these copies are made, mistakes can happen that cause the new copies of the virus to not be exact copies of the “parent” virus. These mistakes are called mutations. Viruses that have mutations are also referred to as “variant viruses” or just “variants.”  Mutations happen all the time and usually don’t result in big changes to the virus. However, some  mutations can happen that change the virus in such a way that they change how the virus works, such as changes to how contagious the virus is, the type of illness it causes, or how our immune systems respond to the virus.

What are variants?

Viruses constantly change through mutation and new variants of a virus, that arise from these mutations, are expected to occur over time. Multiple variants of the virus that causes COVID-19 have been documented in the United States and around the world during this pandemic. Sometimes new variants emerge and disappear. Occasionally, new variants emerge that can pass more easily from one person (or host) to another–the Omicron variant is an example of this.

Learn more about what causes a virus to change in this World Health Organization (WHO) video:

As more people have been infected during the COVID-19 pandemic, more variants have been documented. Scientists continually monitor the virus that causes COVID-19 to look for changes to the virus over time. This helps us better understand how the virus is changing and if these changes might affect how the virus spreads (transmissibility), how sick you could get (disease severity), and how well viral tests, treatments, and vaccines might work on different versions (variants) of the virus.

The best way to stop variants from developing in the first place is to stop the spread of the virus.

Variants Names

Variants have names so that scientists can communicate with one another about trends they see with certain viral lineages. These names can be technical and work well for scientific communications. In May 2021, a group of scientists and experts in communications met to discuss the names we use when communicating with non-scientific audiences about certain variants. They developed a naming system, using letters of the Greek Alphabet (such as Alpha, Beta, Gamma) that are considered to be easier to pronounce and reduce stigma that can develop when a variant is referred to by the country in which it was first identified. Not all variants have a Greek letter name, but ones that the World Health Organization is monitoring closely do. For viruses in the same family, scientists use a letter and number system to tell one from the other. For example, Omicron B.1.1.529 is the name for the “parent” virus and Omicron BA.2 is one of the sub-variants. On this page, we mainly refer to variants by their Greek letter name.

Why are some variants concerning?

A variant of the virus that causes COVID-19 is considered to be concerning when it increases the risk to human health. The risk to human health could be increased because a variant is able to:

  • Spread more easily
  • Cause more severe illness
  • Escape the immune protection provided by available COVID-19 vaccines or by natural infection with the virus that causes COVID-19
  • Make viral tests less accurate
  • Make some treatments less effective

Scientists in the U.S. have a system to categorize variants based on how concerning they are to the U.S. population.  The World Health Organization (WHO) may classify certain variants in different categories because of the impacts they are having in other countries. Because the importance of variants can differ by location, the U.S. classifications may differ from those of the WHO.

The current classification system used in the U.S. is as follows:

Variants being monitored

  • Variants being monitored are variants for which there is evidence that they might be of concern, but are either no longer detected or are circulating at very low levels in the U.S and  do not pose a significant risk to public health in the United States. As of May 5, 2022, the following ten variants are in this category:
    • Alpha
    • Beta
    • Gamma
    • Delta
    • Epsilon
    • Eta
    • Iota
    • Kappa
    • Zeta, and
    • Mu

Variants of Interest

Variants of interest show some evidence that they might be of concern. There are currently no variants of interest in the United States.

Variants of Concern

Variants of concern show evidence of being concerning. There are currently two variants of concern for the United States. These are Omicron (B.1.1.529) and its sublineages. Both are discussed in more detail in the Variants of Concern section below.

Variants of High Consequence

Variants of high consequence show clear evidence of making our disease prevention measures or medical precautions less effective. This may include demonstrated failure of diagnostic tests, more severe clinical disease, and increased hospitalizations. There are currently no SARS-CoV-2 variants of high consequence.

For more information

For more information on these categories and variants in each category, visit CDC SARS-CoV-2 Variant Classifications and Definitions .

About Variants of Concern

Omicron is a new variant that is more transmissible than other variants and might be up to three times more transmissible than Delta. Early reports suggest Omicron infection might be less severe than infection with prior variants; the severity of symptoms can be affected by COVID-19 vaccination status, the presence of other health conditions, age, and history of prior infection. All variants, including Omicron, can cause severe disease or death. People who are up to date with their COVID-19 vaccines and get COVID-19 are less likely to develop serious illness than those who are unvaccinated and get COVID-19.

Learn more about Omicron .

Omicron Letter

Omicron – B.1.1.529

WHO/CDC Label Name of Variant: Omicron

How contagious is this variant? Omicron is more contagious  than the original COVID-19 virus and might be up to 3x more transmissible than Delta.

How sick do people get with this virus? Data suggests that illness might not be as severe as with other variants; symptom severity can vary depending on your vaccination status, age, history of prior infection and the presence of certain medical conditions . However, Omicron is capable of causing severe illness and death.

If I have already had COVID-19 before, am I still protected from this variant? Some reduced protection from natural infection is probable;  reinfection cases have been observed with Omicron. Vaccine “breakthrough infections,” meaning infections in people who are vaccinated, are expected. Being up to date on recommended vaccines is effective at preventing severe illness, hospitalizations, and death.

Are there medications that can treat this variant? Yes. Antiviral drugs work against Omicron and one monoclonal antibody medication is effective.

Will this variant affect a test for COVID-19? No real impact

Why are variants of viruses important?

Everyone should care about variants of concern because if they continue to spread in the United States, there could be another surge (large growth) in cases that could overwhelm our health care systems. This also means that the pandemic could go on longer and might require stronger public health measures to slow the spread. With more COVID-19 cases, there would also be more people who get severely ill and die. Severe infections caused by variants might also be harder for healthcare providers to treat.

At this time, the evidence shows that available COVID-19 vaccines remain effective in protecting the American public from getting severely sick, being hospitalized, or dying from currently circulating variant strains of the virus that causes COVID-19. Every time a person is infected with the virus that causes COVID-19, there is a chance that the virus can mutate and a new variant can develop. With another variant, there is concern that current COVID-19 vaccines and medicines used to treat people with the illness might not work as well.

How can you protect yourself and others?

At this time, the single best way to protect yourself and others is to get vaccinated and to stay up to date with vaccinations. Visit  for more information about how to get vaccinated. General public health recommendations for stopping the spread of COVID-19 will work for all variants. For more information on how to protect yourself and others, visit CDC’s Prevention web page and CDC's Vaccines for COVID-19 web page .

Learn more about stopping the spread of COVID-19 variants in this WHO video:

What are we doing in response to these variants?

  • Working with CDC and our laboratory partners to actively monitor for changes in the genetic material of the virus that causes COVID-19.
  • Tracking what is happening with the spread of variants globally, within the U.S., and in Virginia.
  • Monitoring for any concerning changes in the epidemiologic pattern of the virus that causes COVID-19 in Virginia. 
  • Sharing information with healthcare providers and the public about variants.
COVID-19 Virus illustration

Learn More About Variants

To see how commonly SARS-CoV-2 variants are being identified in the U.S. and where these variants are being identified, visit CDC’s COVID Data Tracker . To see where these variants are being identified in Virginia, visit VDH’s Variants Dashboard. To learn more about variants, visit the CDC's What You Need to Know About Variants .

At this time, available tests are expected to detect existing viral variants. It is very likely that these variants are more common in our communities than the number of reported cases suggest. This is because not all COVID-19 positive samples are tested to see what variant type they are. It is important now, more than ever, that we all continue following public health recommendations to prevent the spread of COVID-19. Public health recommendations for stopping the spread of COVID-19 will work for all COVID-19 variants.

To learn more and help slow the spread of variants:

Page last updated: May 6, 2022

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