EmilyHaag
commented
3 years ago https://outbreak.info/blog/what-are-covid-19-mutations
Definitions paragraphs: The terminology surrounding SARS-CoV-2 mutations is being used very loosely, but distinction is important. A strain of a virus has distinct properties and causes a specific immune response. When a virus has developed a set of mutations that causes it to act differently than that of the original strain, it is classified as a variant. Similarly, lineages are often minor accumulations of mutations, forming a different genetic line of the strain.
If researchers identify a SARS-CoV-2 variant that have concerning pathogenic properties, the variant is classified as a Variant Under Investigation (VUI) with a year, month, and number. Experts investigate the level of risk the variant poses and may elevate it to the classification Variant of Concern (VOC). The B.1.1.7 variant, for example, was originally classified as VUI-202012/01, but has since been renamed to VOC-202012/01. Researchers also use the term Variant of Interest (VOI) to note a variant that requires further study to identify whether it has clinical significance.
The key differences between these classifications: • VOIs and VUIs are variants of increasing prevalence with mutations in biologically important regions but are lacking evidence for increased transmissibility, virulence, and/or immune evasion. • VOCs are variants which have evidence in the literature of increased transmissibility, worse outcomes, and/or decreased vaccine efficacy.
flaneuse
@EmilyHaag has a great paragraph on this in her upcoming blog post. We could possibly use excerpts from that to add here