In the last few days, two Covid-19 variants mainly the Colombian "Mu" mutant and the South African C.1.2 have raised the concern of both scientists and the WHO.
Their rapid genetic evolution undermines the efficiency of current vaccines.
The Mu variant: origin, risks and affected countries
The "Mu" variant was identified in Colombia in January 2021. Since then, it has been reported in several South American and European countries.
The WHO states that the current global prevalence of B.1.621 is less than 0.1%. However, this variant represents 39% of cases in Colombia and 13% in Ecuador.
Although the virus spreads slowly, the speed of mutation presents a risk of immune escape, which has led the WHO to classify "Mu" in the list of variants of interest.
Covid-19: list of variants of interest
| Variant name as-signed by WHO | Pango lineage* | First recorded case |
|---|---|---|
| Eta | B.1.525 | Several countries, December 2021 |
| Iota | B.1.526 | United States, No-vember 2020 |
| Kappa | B.1617.1 | India, October 2020 |
| Lambda | C.37 | Peru, December 2020 |
| Mu | B.1.621 | Columbia, January 2021 |
* includes all descendant lineages.
Characteristics of the South African variant C.1.2
Discovered in South Africa in May 2021, the C12 variant has now been found in Europe, China and the Democratic Republic of Congo. Its mutation rate is twice as fast as any other existing variant, that is 41.8 mutations per year.
C.1.2 is the most distant variant from the original SARS Cov-2 strain. It has the potential for immune escape, although WHO does not yet list it as a variant of concern.
Covid-19: list of variants of concern
| Variant name as-signed by WHO | Pango lineage* | First recorded case |
|---|---|---|
| Alpha | B.1.1.7 | United Kingdom, September 2020 |
| Bêta | B.1.351 | South Africa, May 2020 |
| Gamma | P.1 | Brazil, November 2020 |
| Delta | B.1.617.2 | India, October 2020 |
* includes all descendant lineages.
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