COVID-19 Variant Dashboard

Last content update: 7/29/2021

COVID-19 Variant Report

This dashboard provides the cumulative count of COVID-19 variants that have been identified and reported in Santa Clara County to date.

Since the start of the pandemic, multiple variants of SARS-CoV-2 have appeared. Most do not have significant health impacts, but some may affect COVID-19 transmission, disease severity, testing, treatment, or vaccine effectiveness. On May 25, the CDC published an analysis from January through April 2021 using variant sequencing and vaccination data from around the country, including from Santa Clara County. This study found that there was no variant that was overrepresented among the 5% of fully vaccinated cases that were sequenced, meaning that to date, variants do not appear to decrease the effectiveness of the COVID-19 vaccine in the U.S. Vaccine effectiveness and variants continue to be monitored and studied nationally and globally. For information on vaccinations in Santa Clara County please visit our vaccination dashboard

Following CDC classifications and definitions, the term variant of interest (VOI) is used to describe a new variant that is being monitored to learn more about its impact on health. The term variant of concern (VOC) is used to describe a variant that has already been found to have a significant impact on health, such as being more contagious, more likely to cause severe illness, or less responsive to vaccines or treatment. As CDC and others discover and designate new variants, they will be added to this dashboard. As more information becomes known about particular variants, their designations as VOI or VOC may change.

Known Variants of Concern in Santa Clara County


Variant WHO Label Number of Cases by Variant
B.1.1.7 Alpha 709
B.1.351 Beta 25
P.1 Gamma 103
B.1.617.2 Delta 298
AY.1 Delta 46
AY.2 Delta 1


Known Variants of Interest in Santa Clara County

Variant WHO Label Number of Cases Caused by Variant
B.1.525 Eta 4
B.1.526 lota 34
B.1.526.1 - 24
B.1.617 - 14
B.1.617.1 Kappa 20


Other Variants in Santa Clara County

Variant WHO Label Number of Cases Caused by Variant
P.2 Zeta  2


Last updated on July 29th, 2021. This dashboard is updated every Thursday, but please note that there is a lag in the data of up to a month or more due to the time required for laboratories to sequence and report variant cases to the Public Health Department.


Source: California Reportable Disease Information Exchange; the County of Santa Clara Public Health Department receives notification of case reports determined to be variants of interest/concern from multiple sources including routine genomic surveillance conducted through County of Santa Clara Public Health Lab, the California Department of Public Health, academic partners, and commercial laboratories.

Data included in this dashboard only represent cases reported or known to the County of Santa Clara Public Health Department. As a result, variant case counts presented in this dashboard do not represent the total number of infections due to variant strains that may be circulating in Santa Clara County. Cases reported in this dashboard are preliminary and are subject to change upon further investigation. The West Coast variants (B.1.427 and B.1.429), which are VOCs and number more than 1,000 in Santa Clara County, are not included in this dashboard at this time.

For more information on which variants the California Department of Public Health (CDPH) is tracking and on the number of cases per variant reported across California, see the CDPH website on Tracking Variants.

Where to find more Information

Click here to return to main COVID-19 Data and Reports page

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