What Are the Symptoms of the COVID-19 Omicron Variant? Here's What We Know So Far
On December 1, 2021—just a few days after the World Health Organization (WHO) declared it a variant of concern—the first case of the Omicron variant was confirmed in the US. Now, current data are suggesting that the Omicron variant may soon overtake Delta as the country's dominant COVID strain.
According to the Centers for Disease Control and Prevention (CDC), the new variant has 30 mutations in the spike gene—the part of the virus that allows it to penetrate your cells and infect you—and it is likely more transmissible than the original SARS-CoV-2.
With the introduction of any new variant comes a lot of big questions about how it may be different from the previous variants, including what symptoms it causes and whether it is more or less likely to cause severe illness. Here's what we know so far about the symptoms of the Omicron variant, according to research and infectious disease experts.
What are the symptoms of the Omicron variant?
As Health previously reported, the symptoms of the dominant Delta variant are often like those of a very bad cold. Based on an analysis of COVID-19 symptoms among infected people in London, the symptoms of the Omicron variant might not be too different. That study compared the COVID symptoms that people recorded during a week in October—before the Omicron variant was known to be in London—and a week in December—after the variant was confirmed to be in London. During both weeks, the top five symptoms people reported were runny nose, headache, fatigue, sneezing, and sore throat.
"Hopefully people now recognize the cold-like symptoms which appear to be the predominant feature of Omicron," Tim Spector, lead scientist of the study app behind the data, the ZOE COVID Study app, said in a press release. "... As our latest data shows, Omicron symptoms are predominantly cold symptoms, runny nose, headache, sore throat, and sneezing, so people should stay at home as it might well be COVID."
Research from a large study out of South Africa also showed that the Omicron variant is less likely to cause severe illness than earlier variants, the Washington Post reports. Led by Discovery Health, South Africa's largest health insurer, the study found that most infections are described as mild, with the most common early symptom being a scratchy throat. Other common symptoms include nasal congestion, a dry cough, and aches (particularly lower back pain).
In the December 17 issue of Morbidity and Mortality Weekly Report, the CDC will be releasing a new analysis of the first 43 cases of the Omicron variant that were reported in the US. That research shows that the most commonly reported symptoms among those patients were cough, fatigue, and congestion or runny nose.
This latest data all appear to check out with initial—albeit, anecdotal—reports out of South Africa from when Omicron was first identified. At the time, Dr. Angelique Coetzee, a physician in South Africa and chairwoman of the South African Medical Association, said patients with the Omicron variant seemed to have "very mild symptoms," including "fatigue, head and body aches and occasional sore throats and coughs," as Health previously reported. However, those patients were younger, and as Susan Kline, MD, MPH, an infectious disease physician and professor of medicine at the University of Minnesota Medical School, previously told Health, it's expected that younger groups have milder symptoms.
So does the Omicron variant only cause mild symptoms?
While anecdotal evidence and early data appear to suggest that mild symptoms might be common with the variant, Maria Van Kerkhove, the WHO's COVID-19 technical lead, says that Omicron symptoms can run the whole gamut. "We know that people infected with Omicron can have the full spectrum of disease, from asymptomatic infection to mild disease, all the way to severe disease to death," she said during a question-and-answer session, per CNBC.
Plus, it's still not yet clear whether Omicron truly causes "milder" symptoms than other strains. According to Mohammad Sobhanie, MD, an infectious disease physician at The Ohio State University Wexner Medical Center, it is possible that Omicron could result in different or milder symptoms than previous variants. But that may have more to do with people's vaccination status than the virus itself—because more people than ever are vaccinated, it's possible Omicron just seems milder.
Being fully vaccinated, and especially boosted, reduces the chances a person will experience any COVID-19 symptoms at all—but as we've learned by now, it's possible to get a breakthrough infection, aka an infection when you're fully vaccinated or even boosted. When fully vaccinated and boosted people experience COVID-19 symptoms, Dr. Sobhanie says they may be milder and shorter in duration. "We know that even with breakthrough infections, vaccinated people are less likely to get sick, and if they do get sick, they have a far lower chance of hospitalization and death," he says.
Also, early outbreaks of Omicron have been among young adults who tend to have milder infections anyway, as well as among those who are more likely to have antibody protection through vaccination or previous infection, Anne Liu, MD, an infectious disease physician with Stanford Health Care, tells Health. "Until we see what happens when Omicron spreads to the rest of the community, such as the elderly and vaccinated children, we won't quite understand how this new variant behaves," Dr. Liu says.
It's also important to keep in mind that with every new variant, there's a lag between infections and hospitalizations, so a variant can initially seem less concerning than it actually may be. "Whenever there is a new variant, people say cases are going up but not hospitalizations, but we seem to forget that there's a lag of several weeks before we know if these cases will result in more hospitalizations and deaths," Dr. Liu says.
Truly, more data are needed before more definitive answers about Omicron symptoms and their severity can be given. In a presentation on December 16, the CDC's Advisory Committee on Immunization Practices revealed what is understood: that more data are needed to know if Omicron infections cause more severe illness or death compared to infection with other variants and that vaccines are expected to protect against severe illness, hospitalizations, and deaths. To gather more information, the CDC is closely monitoring real-world vaccine effectiveness and breakthrough infections, as well as Omicron's impact on disease incidence, severity, and vaccine breakthrough.
How can I protect myself against Omicron?
Experts will know more about the Omicron variant and the specific risks it poses (including any new symptoms, especially in unvaccinated people, and how much protection the vaccines provide) as time goes on and they conduct more research. For now, it's important to be aware of existing COVID-19 symptoms and to stay home if you feel ill (even if it just seems like you have a cold). If you need a refresher, the CDC lists the following as possible COVID-19 symptoms:
- Fever or chills
- Shortness of breath or difficulty breathing
- Muscle or body aches
- New loss of taste or smell
- Sore throat
- Congestion or runny nose
- Nausea or vomiting
To protect yourself and others from severe sickness from any COVID-19 strain, Dr. Liu says the best thing to do is get fully vaccinated. And if you're already fully vaccinated, get your booster. If you have children who are eligible, prioritize getting them vaccinated, too.
Even if you're fully vaccinated, continue to wear your mask indoors when gathering with members outside your household or when you're in crowded outdoor settings. If you're getting together with people you don't live with, then Dr. Liu suggests everyone take a rapid COVID-19 test at home to prevent asymptomatic spread (ideally, take a rapid test the same day of the gathering).