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
Variant
Known differences

​​Delta

  • 200% increased transmission compared to other variants

  • Reduced antibody treatment effectiveness

​Omicron

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


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

Variant
Known differences

​Alpha

  • ​Increased transmission

  • Potential increased disease severity and risk of death

  • Minimal impact on antibody treatment effectiveness

​Beta

  • Increased transmission

  • Reduced antibody treatment effectiveness

​Gamma

  • ​Reduced antibody treatment effectiveness

​Epsilon

  • Increased transmission

  • Significantly reduced antibody treatment effectiveness

​Eta

  • ​​Moderately decreased antibody treatment effectiveness

​Iota

  • ​Significantly reduced antibody treatment effectiveness

​Kappa

  • ​Moderately decreased antibody treatment effectiveness

​Zeta

  • ​Moderately decreased antibody treatment effectiveness

Mu

  • 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 January 19, 2022, there have been 385,191 samples sequenced in California. In December 2021, 7% of cases in California had been sequenced, and this percent is expected to increase in coming weeks as more data becomes available. In November 2021, 25%, and October 2021, 21% of 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