Variants and Genomic Surveillance for SARS-CoV-2
The Delta variant causes more infections and spreads faster than earlier forms of the virus that causes COVID-19. It might cause more severe illness than previous strains in unvaccinated people.
- Vaccines continue to reduce a person’s risk of contracting the virus that cause COVID-19, including this variant.
- Vaccines continue to be highly effective at preventing hospitalization and death, including against this variant.
- Fully vaccinated people with breakthrough infections from this variant appear to be infectious for a shorter period.
- Get vaccinated and wear masks indoors in public spaces to reduce the spread of this variant.
Variant Proportions in the U.S.
View data showing proportions of Variants of Concern and Variants of Interest.