What Is the COVID-19 Omicron Variant?

A lot of the details on Omicron variant symptoms and transmissibility remain unclear — here's what's known so far.

omicron variant
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As many families around the U.S. gathered for the first Thanksgiving since the COVID-19 vaccine became widely available, news of another new variant of SARS-CoV-2 (the virus that causes COVID-19), Omicron, began circulating. And given that a prior COVID variant — Delta — has become the most prominent strain of the novel coronavirus worldwide and caused another wave of restrictions, it's understandable if headlines about this new variant are making you feel a little uneasy.

The World Health Organization is currently tracking seven SARS-CoV-2 variants, and Omicron has officially been ranked as a "variant of concern" by the organization, putting it on the same classification level as the highly-transmissible Delta variant. To meet the WHO's definition of a "variant of concern," a strain must be associated with an increase is transmissibility or "detrimental change in COVID-19 epidemiology," an increase in severity or change in the signs and symptoms of the disease, or a decrease in the effectiveness of public health measures to fight the disease. (For reference, the Lambda and Mu variants are both "variants of interest," meaning they're not quite at that level of concern, but they remain on the organization's watch list in case they mutate in a way that boosts transmissibility and/or disease severity.) The WHO also called the global risk posed by Omicron "very high," given that there are already known cases in multiple countries across the world, including Canada, Portugal, Hong Kong, the United Kingdom, and more.

And while that alone might sound pretty unnerving, President Biden discussed developments around Omicron at the White House on Monday, sharing that "sooner or later, we're going to see cases of this new variant here in the United States." His prediction turned out to be right — today the Centers for Disease Control and Prevention (CDC) confirmed that the first detected case of the Omicron variant occurred in California.

With all that said, it's still too early to say what Omicron's full impact will look like. Before you descend into full-on panic mode, read about what experts know about the variant so far. (ICYMI: How Effective Is the COVID-19 Vaccine?)

What Is the COVID-19 Omicron Variant?

First things first, it's important to understand what information is currently available about the Omicron variant. The WHO notes that the first case of B.1.1.529 variant (aka Omicron) reported to the organization came from South Africa on November 24th, with COVID-19 infections rising "steeply" in the country in prior weeks. The first specimen was detected through genomic sequencing (the method by which scientists analyze viral strains) on November 9th, and Omicron has been "increasing in almost all provinces in South Africa'' since it was first detected, according to the WHO. As of this morning, it's been detected in 23 countries, according to CNN.

Of course, all of that sounds particularly ominous, but there is one tidbit of info about Omicron that might help put you at ease. While it's unclear just yet if Omicron causes more severe illness than prior and/or existing COVID-19 variants, there is "currently no information to suggest that symptoms associated with Omicron are different from those from other variants," according to the WHO. So while all COVID-19 variants can and do cause severe illness and death, so far, there's no evidence that COVID-19 Omicron variant symptoms are any more severe than those of prior strains. The reason that the WHO has labeled Omicron a "variant of concern" is that it's sparked a "detrimental change in COVID-19 epidemiology," specifically that it exists as "a large number of mutations" and seems to be more likely to reinfect people who have already had COVID-19, compared to the other variants of concern. The variant "has been detected at faster rates than previous surges in infection," according to the WHO, which may mean it's able to replicate faster. (

What does all this mean, exactly? "The combination of the fact that this variant exploded in South Africa combined with the concerning mutations in the spike protein suggesting a level of increased transmissibility and possibly evasion from our currently deployed defenses is why this has raised several alarms," explains Vivek Cherian, M.D., a Chicago-based internal medicine physician. That said, "we still need time to determine how much of a threat the Omicron variant will pose," says Dr. Cherian — and that includes understanding how existing vaccines will stand up to Omicron. Pfizer-BioNTech, Moderna, and Johnson & Johnson have all released statements saying that they're currently evaluating the performance of their vaccines and boosters against Omicron, and are also pursuing Omicron-specific variant vaccines.

"Understanding the level of severity of the Omicron variant will take days to several weeks," according to the WHO. The TL;DR here: It's too soon for health experts to make concrete calls about Omicron just yet, but there should be more info available soon.

Why Does COVID-19 Keep Mutating & How Should You Protect Yourself?

In case you need a refresher on how and why COVID-19 seems to keep mutating, know that it's not unusual, as every virus can change and evolve, especially if it continues to spread through communities, according to the CDC. When a virus mutates, the viral cells can then bind more easily to cells in your body, which is why variants lend themselves to an increased level of transmissibility, says Dr. Cherian. That's why health experts worry about new variants potentially evading some of our current defenses such as antibodies created by vaccines, monoclonal antibody treatments, and other COVID-19 treatments currently in the pipeline, he adds. (Read more: Why Are the New COVID-19 Strains Spreading More Quickly?)

While so much about Omicron remains unknown at present time, researchers and health experts are working diligently to study this latest variant. "We have a pretty good idea that this variant is highly transmissible, but what we still don't know is will this variant cause severe disease, similar to the Delta variant," says Dr. Cherian. "But we should have the answer very soon."

As you await more concrete info, Dr. Cherian stresses the importance of using the safety tools at your disposal — e.g., vaccines. "Remember, even when you have variants like Omicron, we know that when you have a level of protection from vaccines and the booster, the chance of a severe outcome is reduced significantly," says Dr. Cherian. "Bottom line, the Omicron variant is yet another reason for all of us to get vaccinated and boosted as soon as humanly possible."

The information in this story is accurate as of press time. As updates about coronavirus COVID-19 continue to evolve, it's possible that some information and recommendations in this story have changed since initial publication. We encourage you to check in regularly with resources such as the CDC, the WHO, and your local public health department for the most up-to-date data and recommendations.

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