Updated Nov. 19, 2021

COVID-19 and Variants

Variants of the virus that causes COVID-19 have been a frequent topic in the news lately, but what are they?

As viruses spread from person to person, they can mutate. SARS-CoV-2, the virus that causes COVID-19, is no different. Most mutations are minor and considered inconsequential as these don’t change the behavior of the virus. A group of coronaviruses that have the same mutations are what we refer to as variants.

The majority of variants are not that different from the “original” and they don’t affect us differently. SARS-CoV-2 does not mutate remarkably quickly. In fact, influenza (flu) viruses mutate twice as fast as SARS-CoV-2.

Types of Variants

In some cases, a variant is biologically different enough from the original that it can affect our health more than other variants or is less responsive to treatment. The Centers for Disease Control and Prevention (CDC) categorizes variants according to four classifications: these classifications are variants being monitored, variants of interest, variants of concern and variants of high consequence.

The more the virus spreads, the greater the number of mutations that occur. Reducing virus spread through vaccination reduces the number of mutations and can help prevent future variants that are more likely to affect our health or evade the immune protection provided by vaccines.

Variants Being Monitored (VBM)

Variants being monitored include variants that data have shown to be associated with more severe illness or greater transmission, capable of impacting the effectiveness of COVID-19 vaccines or treatments but are no longer detected, or circulating at such low levels in the United States that they no longer present a significant risk to public health.

Variants of interest and variants of concern may be moved to this list if the proportions of national and regional infections associated with them show a consistent downward trend or if evidence suggests they are less of a risk to public health in the United States.

Variants of Interest (VOI)

CDC defines variants of interest as having one or more of the following attributes:

  • Genetic markers that are expected to affect how they spread, are diagnosed, respond to treatment, and immune escape ( an infected person’s immune system may not recognize and respond to the virus)
  • Evidence linking them to increased numbers of cases or unique outbreak clusters
  • Generally limited in their spread in the United States or other countries.

Variants of Concern (VOC)

CDC defines a variant of concern as a variant that has one or more of the following attributes in addition to the possible attributes of a variant of interest:

  • Evidence that they affect diagnostics, treatments and vaccines. For example, they may
    • Cause widespread interference with diagnostic testing
    • Demonstrate increased resistance to treatments in those who are infected
    • Not respond to the antibodies in the body of a person who has been vaccinated or previously infected
    • Be more likely to cause severe illness in vaccinated people
  • Evidence that they spread more easily
  • Evidence that they cause more severe disease

The Delta variant of SARS-CoV-2 is categorized as a variant of concern. Learn more about the Delta variant.

Variants of High Consequence (VOHC)

CDC defines variants of high consequence as having the following possible attributes in addition to the attributes of a variant of concern:

  • Clear evidence showing reduced effectiveness of prevention and treatment measures including the following:
    • Diagnostic tests
    • Vaccines (causing a disproportionately high number of infections in vaccinated people or less protection from severe disease)
    • Authorized therapeutic treatment
  • More severe clinical disease and increased hospitalization

None of the SARS-CoV-2 variants are categorized as variants of high consequence at this time.


CDC is currently monitoring several variants of concern worldwide. Similarly, the Washington State Department of Health (DOH) is monitoring variants that have been detected in Washington state and publishes a weekly report. Cases involving several different variants have been identified in Spokane County. See the most recent variant report from DOH for more information.

What Does This Mean for You?

Due to federal regulations, you will not be notified if you test positive for a SARS-CoV-2 variant. Even if you were, you would still follow the same guidance for patient care.

As more variants are detected in our region, it’s important to continue following prevention measures if you're unvaccinated:

  • Wear a well-fitting mask when within six feet anyone from outside of your household.
  • Keep gatherings small and outdoors.
  • Avoid indoor social gatherings—if participating, keep doors and windows open for the best possible ventilation.
  • Wash your hands often or use hand sanitizer when soap and water aren’t available.
  • Avoid touching your face.
  • Stay home if you are sick or have been exposed to COVID-19.
  • Get tested if you think you’re sick or if you think you were exposed.
  • Sign up for WA Notify.
  • Get vaccinated as soon as you can. While some variants are less affected by current vaccines, getting vaccinated is the best protection from COVID-related hospitalization and death.

Learn more about COVID-19 variants

Watch this video for an in-depth look at COVID-19 variants with SRHD Interim Health Officer Dr. Francisco Velázquez.

Content adapted from materials provided by the Washington State Department of Health (DOH) and the Centers for Disease Control and Prevention (CDC).

The Delta Variant

Download this page as a factsheet

The Delta variant is a mutation of the original virus.

Over time, viruses mutate as they pass from person to person. SARS-CoV-2, the virus that causes COVID-19, is no different. These mutations are called variants. Some variants continue to circulate while others die out. Other variants persist and become the dominant version of the virus. The Delta variant is currently the most dominant variant in the United States.

It was detected in October of 2020 in India and is now present in Spokane County.

The Delta variant was first detected in India in October of 2020. Since then, it has spread around the globe. The Delta variant was first detected in Washington in April 2021 and is circulating in Spokane County.

It’s more contagious.

The Delta variant is highly contagious. It is believed to cause more than twice as many infections.

It may cause more severe illness in unvaccinated people than previous variants.

There is evidence from studies conducted in England and Scotland that unvaccinated patients with the Delta variant may be more likely to be hospitalized than patients infected with other variants.

People who are not vaccinated are at the greatest risk.

Unvaccinated people are most at risk for becoming infected with and spreading the Delta variant to others.

People who are vaccinated can become infected, but symptoms are typically mild.

People who are vaccinated can, in rare cases, become infected with the Delta variant and spread it to others. However, evidence suggests that while vaccinated individuals develop the same high amount of virus as unvaccinated individuals, the amount of virus goes down sooner, meaning they are likely to be infectious for a shorter period of time and their symptoms are milder.

More variants may emerge if we don’t stop the spread.

Viruses mutate as they spread from person to person. Stopping transmission is the best way to prevent more variants that are even more transmissible and potentially more dangerous.

We have the tools to stop it.

The rules to slow the spread of the Delta variant are the same as they have been throughout the pandemic.

Get vaccinated: Our vaccines are showing good protection from the variant. Even if an unlikely breakthrough case (getting infected while fully immunized) occurred, the vaccine would provide good protection against severe illness. The vaccine is the best line of defense. Learn more

Wear a mask, get tested, wash your hands, practice social distancing: We still have other tools available like masking, testing, handwashing, and social distancing. These are especially valuable in public, indoor settings when you don’t know the vaccination status of other people. Each precaution you take is an added layer of protection—and guess what? Each of these tools adds another layer of protection from the Delta variant.

Delta Variant Factsheet