What We Know—And Don’t Know—About the Omicron Variant

Thanksgiving merriment was tempered with news of the new omicron COVID-19 variant, which was first detected in South Africa and found quickly in more than 20 countries. This has raised concerns among scientists and healthcare providers who were hoping to bring the pandemic under control in the coming months.

We talked to UNC Health infectious diseases specialist David A. Wohl, MD, about what we know and don’t know about the omicron variant—and what people can do to stay safe.

What We Know About Omicron

1. The omicron variant has a high number of mutations, which may make it more transmissible.

The omicron variant is different than other variants we have seen in that it has more of the mutations that lead to changes in the shape of parts of the virus to which our bodies react. That means our immune systems may not recognize this variant as well as previous variants even among those of us who are vaccinated or were infected with COVID-19. Some of the mutations we are seeing in omicron also have been associated with greater transmissibility.

“The larger number of mutations in the omicron variant may mean that it could be more transmissible or better at evading immune protection,” Dr. Wohl says.

2. Is omicron in the United States?

Yes, a person in San Francisco became the first in the United States to have an identified case of the omicron variant. This person had traveled to South Africa and was vaccinated but had not received a booster shot. To date, this person has had only mild symptoms of COVID-19.

The Centers for Disease Control and Prevention (CDC) is considering plans to strengthen COVID-19 testing requirements and screening of international fliers bound for the United States because of concern about the omicron variant.

Given reports of omicron in various parts of the world, it is clear that it is also here and will spread.

3. Vaccination, masking and testing are the best ways to protect yourself and others.

While we still have much to learn about how well prior infection and vaccination protect against omicron, we know that higher levels of antibodies against COVID-19 were protective against prior variants. Although omicron has mutated more than earlier variants, there are parts of the virus that are the same as these other variants.

“My hope, if not my expectation, is that vaccination and especially having had a booster shot will provide protection from getting sick from omicron,” Dr. Wohl says. “We can expect to see more infections due to this variant, just as we are seeing more infections from the delta variant lately. But, being fully vaccinated will very likely be the difference between getting mildly ill and getting very sick.”

The best way to protect yourself against any variant is to get vaccinated, get a booster if you’re eligible and wear a mask in public.

If you’ve had a Pfizer or Moderna vaccine more than six months ago or a Johnson & Johnson vaccine more than two months ago, you should get a booster shot, which provides additional protection against severe disease.

Dr. Wohl also advises that people get tested before attending gatherings.

“If you’ve got any symptoms, such as the sniffles or a sore throat, get a rapid test,” which you can buy at a drugstore, Dr. Wohl says. “These tests can pick up infection. If you gather together and everyone’s tested beforehand that day, chances are people are not dripping with lots of virus that they could spread to others.”

What We Don’t Know About Omicron

1. The severity of the omicron variant has not yet been evaluated.

At this time, the omicron variant does not appear more severe than other variants, but it is too early to know for sure. More information on the clinical course of those infected with omicron will become available soon.

There are early signs that the omicron variant may cause only mild illness (body aches and extreme fatigue). However, this is based mainly on South Africa’s cases among young people, who are less likely overall to become severely ill from COVID-19 anyway.

2. The effectiveness of the COVID-19 vaccines against the new variant still needs to be determined.

We do not know if COVID-19 vaccines will be less effective against omicron. One theory is that the vaccines will be less effective in preventing transmission of the omicron variant but may help prevent serious illness, especially for those who have received a booster dose of a COVID-19 vaccine.

“I’m cautiously optimistic that people who are vaccinated make a broad enough response that they should be able to avoid severe illness with this new variant,” Dr. Wohl says.

Researchers will test the blood of vaccinated people and those who had a natural COVID-19 infection to see if the antibodies neutralize omicron; Dr. Wohl expects data from South Africa first.

In addition, vaccine makers have said they can modify existing formulations to make the vaccines more effective against new variants, if needed.

Even if scientists learn that omicron evades some vaccine protection, it’s still a much safer bet to be vaccinated to prevent serious illness and death, Dr. Wohl says.

“Remember, the most dangerous variant right now is delta,” Dr. Wohl says. “Delta is circulating widely and has led to the deaths of hundreds of thousands of people and sickened many more over the past several months. We know vaccination protects against delta.”

3. Current monoclonal antibody therapies need to be evaluated.

We do not know if current monoclonal antibody therapies to treat COVID-19 will be as effective. They may need to be updated if the new variant spreads aggressively.

“Some of our monoclonal antibodies may not work against omicron, including the Regeneron compound that we use at UNC Health,” Dr. Wohl says. “So that may require a shift to monoclonal antibodies that do work against this particular variant, if it spreads. That’s going to be very important therapeutically, and we’re already thinking about that—there are likely good alternatives. More data will emerge soon on which monoclonals work best against omicron.”

Visit unchealthcare.org/vaccine for the latest information on the COVID-19 vaccines.