Tech & Science dictionary

Omicron variant

or omicron variant or Omicron Variant [ om-i-kron OR oh-mi-kron vair-ee-uhnt ]

What is the Omicron variant?

The Omicron variant is a variant of the COVID-19 virus. Omicron variant is the common name used to refer to what was originally known by the technical name B.1.1.529 variant.

A variant of a virus is a new strain that has emerged due to a mutation (or mutations) in the virus’s genetic structure.

Use and awareness of the name Omicron variant became more common in news reports and public health communications in late 2021, including those about whether it could potentially be more contagious or more severe than previous variants, such as the Delta variant.

What is the Omicron subvariant?

The Omicron variant has several subvariants, which are subtypes that have additional mutations not found in the original variant but are still similar enough not to be considered completely distinct variants. By mid-2022, two subvariants—named BA.4 and BA.5—had become dominant in many places, including the US. In most of these cases, BA.5 became the most dominant. BA.4 and BA.5 were first identified and reported in South Africa in January and February 2022 and were later given their alphanumeric designations by the WHO. They were reported in the US by late May and early June 2022, with BA.5 quickly becoming the most dominant variant of COVID-19, accounting for more than half of cases at that time. According to experts, both BA.4 and BA.5 are more contagious and have a higher resistance to vaccines than other Omicron subvariants. In response, the Food and Drug Administration recommended that vaccine makers account for both subvariants when producing COVID-19 booster shots for the fall season. 

Before BA.4 and BA.5, the most widely prevalent and discussed subvariant was the one named BA.2, sometimes called stealth Omicron (or the stealth variant) in casual use due to the increased difficulty of distinguishing it from other variants in lab tests. (Public health officials and medical experts have cautioned against the use of nicknames like stealth Omicron, which they say can cause panic and misconceptions about such variants.)

The BA.2 variant became the subject of public health scrutiny and media reports in early 2022 due to having replaced the original Omicron variant as the dominant strain in some places.

Related words

Lambda variant, Delta variant, ChAdOx1 nCoV-19, coronaversary, breakthrough case, twindemic

Where does Omicron variant come from?

According to the World Health Organization (WHO), the Omicron variant was first reported in South Africa in November 2021 and detected in Canada soon after. In the name Omicron variant, the word omicron refers to the 15th letter of the Greek alphabet. The name was used by the WHO as part of their system of using Greek letters to identify major COVID-19 variants. Other major variants were named Alpha, Beta, Gamma, Delta, Lambda, and Mu.

The B.1.1.529 Variant was first labeled by the WHO as a “Variant Under Monitoring” (VUM). This category includes a large number of COVID-19 variants that may or may not have a higher risk of infection or severity. B.1.1.529 was named Omicron when it was reclassified as a “Variant of Concern” (VOC), a category reserved for variants associated with a higher risk to public health. The VOC classification includes the most severe variants of COVID-19.

The name Omicron variant came to be well-known in late 2021 due to wide coverage of the variant by international media and international response to its classification by the WHO. Many countries, including the United States, restricted or banned travel to or from South Africa and some neighboring countries in an attempt to limit the spread of the Omicron variant.

Examples of Omicron variant

Much more to learn about the new Omicron variant. Right now it is best to maximize protection by getting vaccinated if you haven’t already, or boosted if you are eligible.
@cyrusshahpar46, November 26, 2021
The World Health Organization is warning that the new omicron variant of the coronavirus poses a "very high" global risk because of the possibility that it spreads more easily and might resist vaccines and immunity in people who were infected with previous strains.
Scott Neuman, NPR, November 29, 2021

Who uses Omicron variant?

The name Omicron variant is the most common way to refer to widespread the COVID-19 variant. It’s widely used by health experts and in media reports.


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