COVID-Variants Tracking Variants

Tracking Variants

Variants Are a Normal Part of Viruses 

Viruses change through mutations that create new strains of virus over time. This is a normal process that happens with most viruses. We call these strains variants.

Some variants rise and then disappear. Other variants become common. Most variants do not have a meaningful impact.

Why Are We Tracking Variants?

Scientists and public health officials are studying variants to learn more about how 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

Variants We Are Tracking  

Variants of Concern

Variants of concern are likely to have one or more of the following features:

  • More contagious
  • Likely to cause more severe symptoms
  • Resistant to treatment
  • More resistant to vaccines


​Known differences


  • 200% increased transmission compared to other variants

  • Reduced antibody treatment effectiveness


The California Department of Public Health is working with the CDC to gather up-to-date information about the Omicron variant.

  • At least 2 to 4 times more transmissible than the Delta variant

  • Reduced effectiveness of certain antibody treatments

The Omicron variant (Pango Lineage B.1.1.529) has been classified into the following sublineages: BA.1, BA.1.1, BA.2, BA.3, BA.4, and BA.5. As of Aug 3, 2022 for the month of July in California, the BA.2.12.1 sublineage makes up 14.7% of confirmed Omicron cases sequenced, and BA.4 and BA.5 sublineages make up 11.8% and 70.3%, respectively. However, there is a known delay in sequencing results being available, thus, CDC models projections for the most recent weeks for which sequencing data are not yet available. Based on this, the CDC updated the COVID Data Tracker projecting that BA.2.12.1 may be decreasing in the U.S. [2.6% (2.4-2.8%)] for the week ending Jul 30, 2022, and in Region 9 which includes California [2.3%(2.1-2.6%)]. CDC also projects that BA.4 may be decreasing (7.7%(7.0-8.5%) while BA.5 (85.5%(83.8-87.0%) is increasing in the U.S. including in Region 9 which includes California. Specifically, in California BA.4 is projected at 7.1%(6.4-7.8%) and BA.5 is projected at 89.1%(88.2-89.9%) by CDC.

BA.2.12.1 has an estimated growth advantage of 23-27% over BA.2, but there is no evidence of increased disease severity due to BA.2.12.1 at this time. BA.4 and BA.5 sublineages, first identified in South Africa earlier this year have been reported in California. These sublineages are 10% more transmissible than BA.2 and can partially evade immunity from vaccination or previous infection (including prior BA.1 infection). There is no evidence of increased disease severity due to these sublineages at this time.

Please note, that one of the COVID-19 anti-SARS-CoV-2 monoclonal antibodies, sotrovimab, has been shown to be less effective in treating COVID-19 infections due to the BA.2 sublineage. Because of this, the U.S. Food and Drug Administration (FDA) has removed the authorization for sotrovimab in the U.S., including California. Providers should prioritize use of Paxlovid and remdesivir for treatment of mild to moderate COVID-19 in outpatients at risk for disease progression, as these drugs are effective against all Omicron sublineages. If an anti-SARS-CoV-2 monoclonal antibody is indicated over these two antiviral treatments, providers should use bebtelovimab.

Variants Being Monitored

Variants being monitored are seen at low levels or no longer detected. They do not pose a significant or immediate risk to the public. They are likely to have one or more of the following features:

  • Potential or known effect on treatment
  • More severe symptoms
  • Increased transmission


​Known differences


  • ​Increased transmission

  • Potential increased disease severity and risk of death

  • Minimal impact on antibody treatment effectiveness


  • Increased transmission

  • Reduced antibody treatment effectiveness


  • ​Reduced antibody treatment effectiveness


  • Increased transmission

  • Significantly reduced antibody treatment effectiveness


  • ​​Moderately decreased antibody treatment effectiveness


  • ​Significantly reduced antibody treatment effectiveness


  • ​Moderately decreased antibody treatment effectiveness


  • ​Moderately decreased antibody treatment effectiveness


  • Moderately decreased antibody treatment effectiveness

California follows the CDC's variant classifications and definitions.

CDC and CDPH do not consider variants being monitored as variants of concern at this time.

California Sequencing 

As of August 3, 2022, there have been 684,763 samples sequenced in California. In June 2022 6% of 475,879 cases in California were sequenced, and this percent is expected to increase in coming weeks as more sequence data becomes available. In May 2022 9% of 365,328 cases were sequenced, and in April 2022 16% of 124,566 cases in California were sequenced. This is the number of sequences submitted to the data repository GISAID and is not a complete list of sequences completed to date.

Variant Genetic Sequence Data