Variant of Concern
A variant for which there is evidence of an increase in transmissibility, more severe disease (increased hospitalizations or deaths), significant reduction in neutralization by antibodies generated during previous infection or vaccination, reduced effectiveness of treatments or vaccines, or diagnostic detection failures.
Possible attributes of a variant of concern:
In addition to the possible attributes of a variant of interest
Evidence of impact on diagnostics, treatments, and vaccines
Widespread interference with diagnostic test targets
Evidence of substantially increased resistance to one or more class of therapies
Evidence of significant decreased neutralization by antibodies generated during previous infection or vaccination
Evidence of reduced vaccine-induced protection from severe disease
Evidence of increased transmissibility
Evidence of increased disease severity
Variants of concern might require one or more appropriate public health actions, such as notification to WHO under the International Health Regulations, reporting to CDC, local or regional efforts to control spread, increased testing, or research to determine the effectiveness of vaccines and treatments against the variant. Based on the characteristics of the variant, additional considerations may include the development of new diagnostics or the modification of vaccines or treatments.
Source: Centers for Disease Control and Prevention