Variants of Concern

Delta / B.1.617.2
First identified in India and has potential reduction in neutralization by monoclonal antibody treatments and post-vaccination sera, as well as increased transmissibility.

Variants Being Monitored

Gamma / P.1
First identified in Brazil and has significantly reduced susceptibility to monoclonal antibody treatment. Reduced neutralization by convalescent and post-vaccination sera has been observed.


Beta / B.1.351
First identified in South Africa and has significantly reduced susceptibility to monoclonal antibody treatment, as well as increased transmissibility. Reduced neutralization by convalescent and post-vaccination sera has been observed.


Alpha / B.1.1.7
First identified in the United Kingdom and exhibits increased transmissibility in addition to potential increased severity based on hospitalizations and case fatality rates. Minimal impact on neutralization by convalescent and post-vaccination sera has been noted.


Variant images from outbreak.info (Mullen et al 2020)

The variants described above are reflective of the CDC’s SARS-CoV-2 Variant Classifications and Definitions. These variants have been characterized based on the presence of a number of attributes, including evidence of an increase in transmissibility, more severe disease, significant reduction in neutralization by antibodies generated during previous infection or vaccination, reduced effectiveness of treatments or vaccines, and/or diagnostic detection failures.