COVID-19 Variants of Concern
Variant Proportions Chart
Information about the characteristics of these variants is rapidly emerging. Scientists are working to learn more about how easily they spread, whether they could cause more severe illness, and whether currently authorized vaccines will protect people against them.
CDC deescalated Epsilon B.1.427 and B.1.429 from a VOC on June 29, 2021 due to the significant decrease in the proportion of Epsilon lineage viruses circulating nationally and available data indicating that vaccines and treatments are effective against this variant. As of July 28, 2021, IDPH will no longer include this data under Variants of Concern.
Beginning August 20, 2021, IDPH included Delta sub-variants AY.1, AY.2, and AY.3 under Variants of Concern, similar to CDC.
CDC deescalated Alpha B.1.1.7, Beta B.1.351, and Gamma P.1 from VOC due to significantly reduced circulation in the United States and Illinois. As of December 10, 2021, IDPH will no longer include this data under Variants of Concern.
What We Know
Viruses constantly change through mutation, and new variants of a virus are expected to occur over time. Sometimes new variants emerge and disappear. Other times, new variants emerge and persist. Multiple variants of the virus that causes COVID-19 have been documented in the United States and globally during this pandemic.
The virus that causes COVID-19 is a type of coronavirus, a large family of viruses. Coronaviruses are named for the crown-like spikes on their surfaces. Scientists monitor changes in the virus, including changes to the spikes on the surface of the virus. These studies, including genetic analyses of the virus, are helping scientists understand how changes to the virus might affect how it spreads and what happens to people who are infected with it.
Multiple variants of the virus that causes COVID-19 are circulating globally:
The B.1.617.2 (Delta) and B.1.1.529 (Omicron) variants circulating in the United States are classified as variants of concern.
These variants seem to spread more easily and quickly than other variants, which may lead to more cases of COVID-19. An increase in the number of cases will put more strain on health care resources, lead to more hospitalizations, and potentially more deaths.
So far, studies suggest that antibodies generated through vaccination with currently authorized vaccines recognize these variants. This is being closely investigated and more studies are underway.
Rigorous and increased compliance with public health mitigation strategies, such as vaccination, physical distancing, use of masks, hand hygiene, and isolation and quarantine, is essential to limit the spread of the virus that causes COVID-19 and protect public health.
What We Do Not Know
Scientists are working to learn more about these variants, and more studies are needed to understand:
- How widely these new variants have spread
- How the disease caused by these new variants differs from the disease caused by other variants that are currently circulating
- How these variants may affect existing therapies, vaccines, and tests
What It Means
Public health officials are studying these variants quickly to learn more to control their spread. They want to understand whether the variants:
- Spread more easily from person-to-person
- Cause milder or more severe disease in people
- Are detected by currently available viral tests
- Respond to medicines currently being used to treat people for COVID-19
- Change the effectiveness of COVID-19 vaccines
What IDPH is Doing
IDPH, in collaboration with the CDC, is monitoring Illinois closely. IDPH is working to monitor the spread of identified variants, characterize emerging viral variants, and expand its ability to find new SARS-CoV-2 variants.
Last Updated: December 10, 2021
Content source: Centers for Disease Control and Prevention