As of Nov. 26, 2021, there have been five SARS-CoV-2 variants of concern (VoC) that have surfaced and undergone transmission across the globe.

The most recently-discovered variant of coronavirus, Omicron, carries at least 50 mutations, making it a variant of concern — the most serious category assigned by the World Health Organization for coronavirus tracking.

Omicron has 30 mutations on the spike protein, and 26 unique mutations. In comparison to 10 unique mutations found in the Delta variant.

As of Nov. 29, 2021, no data is available to show the extent Omicron can evade immunity from the infected or the vaccinated.

On Nov. 28, 2021, WHO said that while researchers are trying to understand the transmissibility and severity of Omicron on individuals, “vaccines remain critical to reducing severe disease and death.”

So far, Omicron has been found in multiple countries, including Canada, Japan, France, Scotland, Portugal, and the U.S.

covid 19 variant of concern timeline

Graphic by Jasna Baric