Understanding Coronavirus Variants: WHO Definitions
Overview
Coronavirus, including the virus causing COVID-19, undergoes changes over time. While most changes have minimal impact, some alterations can affect various aspects of the virus.
WHO Classifications
Variants of Interest (VOI)
VOIs are identified based on specific changes:
- Increased transmissibility or changes in epidemiology.
- Enhanced virulence or alterations in disease presentation.
- Decreased effectiveness of public health measures, diagnostics, vaccines, or therapeutics.
Variants of Concern (VOC)
VOCs exhibit significant changes:
- Elevated transmissibility or shifts in epidemiological patterns.
- Heightened virulence or modifications in disease manifestation.
- Reduced efficacy of public health measures, diagnostics, vaccines, or therapeutics.
Note: Variant classification may change over time as new data emerges.
For more information, visit www.who.int.