SARS-CoV-2 Omicron variant

Omicron (B.1.1.529) is a <a href="/facts/Variants_of_SARS-CoV-2/zN65y7eG">variant of SARS-CoV-2</a> first reported to the <a href="/facts/World_Health_Organization/YNN3bgug">World Health Organization</a> (WHO) by the Network for Genomics Surveillance in South Africa on 24 November 2021. It was first detected in <a href="/facts/Botswana/dGw6g94p">Botswana</a> and has spread to become the predominant variant in circulation around the world. Following the original B.1.1.529 variant, several subvariants of Omicron have emerged including: <a href="/facts/BA.1/N6u1sGPt">BA.1</a>, <a href="/facts/BA.2/N6u1sGPt">BA.2</a>, <a href="/facts/BA.3/N6u1sGPt">BA.3</a>, <a href="/facts/BA.4/N6u1sGPt">BA.4</a>, and <a href="/facts/BA.5/N6u1sGPt">BA.5</a>. Since October 2022, two subvariants of BA.5 called <a href="/facts/BQ.1/N6u1sGPt">BQ.1</a> and <a href="/facts/BQ.1.1/N6u1sGPt">BQ.1.1</a> have emerged.
As of September 2024, a new subvariant of Omicron labeled XEC has emerged. The new variant is found in Europe, and in 25 states in the United States, including three cases in California.
Three doses of a <a href="/facts/COVID-19_vaccine/obToxWTT">COVID-19 vaccine</a> provide protection against severe disease and hospitalization caused by Omicron and its subvariants. For three-dose vaccinated individuals, the BA.4 and BA.5 variants are more infectious than previous subvariants but there is no evidence of greater sickness or severity.

As of 23 May 2025, the variants of interest as specified by the <a href="/facts/World_Health_Organization/YNN3bgug">World Health Organization</a> are JN.1, and the variants under monitoring are KP.3, KP.3.1.1, JN.1.18, LB.1, LP.8.1, NB.1.8.1 and XEC.<a class="footnote-ref" id="fnref:13" href="#fn:13">13</a>

SARS-CoV-2 Omicron variant open-in-new

SARS-CoV-2 Omicron variant