NEWS

What Do We Know About the Omicron Variant So Far?

variant illo

Verywell Health / Theresa Chiechi

Key Takeaways

  • Omicron is a new COVID variant of concern.
  • The Omicron variant contains more unusual mutations than previous strains, and it could be more transmissible and vaccine-resistant potentially.
  • Vaccine manufacturers like Pfizer and Moderna have announced plans for a potential Omicron-specific shot.

The World Health Organization (WHO) on November 26 classified the COVID-19 Omicron variant—B.1.1.529—as a variant of concern (VOC).

South Africa was the first country to report the Omicron variant to the WHO, but a Dutch health agency confirmed that the variant was already present in the Netherlands a week earlier.

According to the WHO, Omicron contains multiple mutations that could increase transmissibility and risk of reinfection.

Mutations are natural occurrences in many viruses, not just COVID-19. While the effectiveness of the existing vaccines against the Omicron variant is still being studied, no variant has been strong enough to render the vaccines totally ineffective.

Where Has Omicron Been Detected?

The variant has spread to dozens of countries. The first confirmed U.S. case of Omicron was detected in California on December 1.


The U.S. has issued travel bans on South Africa and several other countries in the region, a move criticized by the WHO.

"Blanket travel bans will not prevent the international spread, and they place a heavy burden on lives and livelihoods," the WHO said in a statement. "In addition, they can adversely impact global health efforts during a pandemic by disincentivizing countries to report and share epidemiological and sequencing data."

Why Do Viruses Mutate?

Mutations are natural occurrences in viruses. Similar to how our bodies build antibodies to fight against a virus, a virus will form mutations to try to get around antibodies and keep living inside of us.

When it comes to COVID-19 mutations, the concern is that a variant may eventually become strong enough to bypass vaccine protection. This has yet to happen, and ongoing studies are trying to determine vaccine efficacies against the Omicron variant.

Is Omicron More Dangerous Than Other Variants?

Researchers are unsure if Omicron is more transmissible than other COVID-19 variants, including Delta. Preliminary data on Omicron suggests that it may pose a higher risk of reinfection than other circulating variants, but there's not enough information to confirm or dispute this claim, according to the WHO.

So far, symptoms associated with Omicron do not appear to be different than those associated with other variants. But fully understanding Omicron's range of symptoms, risk, and transmission levels will take several weeks.

In areas where Omicron has been located, both COVID-19 cases and hospitalizations are growing. But the WHO said it’s unclear whether the increases are results of the variant.

WHO's COVID-19 tracker shows that South Africa saw a surge of over 18,000 cases on the day it reported the variant. Since Nov. 26, the country has recorded more than 2,000 cases per day.

Andrew Pekosz, PhD, a virologist and researcher at Johns Hopkins Bloomberg School of Public Health, told Verywell that it’s hard to predict the severity of a virus mutation without real-world data.

The Beta and Gamma variants, for example, raised concerns when they were discovered, and did cause some local outbreaks, but they didn’t become a dominant global virus, he added. In contrast, the Alpha and Delta variants turned out to be highly infectious.

“We just don't know where Omicron is going to fall right now,” Pekosz said. “We have to wait for the initial epidemiology and contact tracing results to start coming in before we can make an estimate as to how dangerous it's going to be as a global pathogen.”

Pekosz expects that more data on the variant’s impact could arrive next week.

Will Vaccines Work Against the Omicron Variant?

Vaccines may be less effective against Omicron than other variants, although more data is needed.

Pekosz said Omicron has “a tremendously larger number of mutations than any variant that has come through,” which contributes to the uncertainties.

Omicron has about 50 mutations, some of which have not been seen in other variants, South African scientist Tulio de Oliveira said at a media briefing. More than 30 mutations are within its spike protein, which provides an entry point from the coronavirus to human cells. He added that Omicron has a “very unusual constellation of mutations” and it’s very different from other circulating variants.

What makes the Omicron mutations so concerning is that they fall into three different categories that can inhibit vaccine protection and speed up the spread of the virus, Pekosz said.

According to Pekosz, the categories are:

  1. Mutations that eliminate binding sites for antibodies, potentially weakening vaccine efficacies against Omicron.
  2. Mutations that make the virus replicate and enter cells faster.
  3. Mutations that allow the virus to bind more tightly to specific cells in the respiratory tract. 

Mutations from the Delta variant fall in the first two categories, but the third mutation is unique to Omicron, he added.

“It has these three very concerning signatures, at least on paper, that cause us to think that this might be a variant that could be more transmissible and could escape some vaccine- or infection-induced immunity, at least to a certain degree,” Pekosz said.

U.S. vaccine manufacturers Moderna and Pfizer-BioNTech have both announced potential plans for an Omicron-specific vaccine, which could be ready in a few months. 

Pfizer CEO Albert Boula told CNBC that the company expects to have results on the effectiveness of its shot against Omicron in about two weeks. If the results prove a variant-specific vaccine is necessary, Pfizer could have it ready for shipment in about 100 days, Boula said.

Moderna, Pfizer, and Johnson & Johnson are planning to test their vaccines against an artificial version of Omicron to better determine their effectiveness, The New York Times reported.

For people looking for extra protection against the Omicron variant, Pekosz encourages full vaccinations and booster shots.

“While Omicron may not be a perfect match to the vaccine strain, there are some antibodies that are going to cross react,” Pekosz said. “If you want to be proactive, go and get your vaccine, go get your booster."

Pekosz advised not to jump to conclusions or bet on winter shutdowns just yet. He pointed to vaccinations as a reason to feel more confident in the fight against the COVID-19 pandemic.

“We're in a very different place now than we were at the beginning of the pandemic,” Pekosz said. “I think we have a lot more immunity in the population. Even if it's not a perfect match to the virus that is circulating, that immunity is going to lessen disease severity and lessen mortality. “

What This Means For You

Omicron, a new COVID-19 variant, has been designated as a variant of concern by the WHO. The variant has yet to be reported in the U.S., but its several vaccine-fighting mutations are prompting health authorities to prepare for mitigation strategies such as vaccine boosters.

The information in this article is current as of the date listed, which means newer information may be available when you read this. For the most recent updates on COVID-19, visit our coronavirus news page.

Was this page helpful?