- Experts say the Omicron variant shares some symptoms with other COVID-19 variants, especially those affecting the upper respiratory system.
- They say fever, cough, and headache are among the common symptoms. So are muscle aches.
- However, people who have been diagnosed with Omicron so far don’t report a significant loss of taste and smell.
- Experts say Omicron symptoms appear to be relatively mild so far, particularly for vaccinated people.
The Omicron variant of COVID-19 acts more like a head cold than previous manifestations of the coronavirus.
And symptoms may differ, too.
Studies have found that the most common symptoms Omicron causes are similar to those caused by other variants.
- runny nose
- sore throat
Muscle pain also seems to be common.
“In vaccinated and boosted individuals, Omicron tends to cause a dry/scratchy sore throat, sneezing, headache, muscle aches, fatigue, and runny nose/congestion,” Dr. N. Adam Brown, the chief impact officer and COVID-19 Task Force chair at Envision Healthcare, a national medical group, told Healthline.
“A dry cough and fever can also accompany Omicron but are less common than with earlier variants,” he added.
“Most people who become infected begin with a dry sore throat, body aches, and headache,” said Brown. “Those symptoms progress for a few days.”
Loss of taste and smell seem to be less common with Omicron. Severe lung problems are also rarer.
“In our [patient] interviews recently we have been hearing less reports of loss of taste or smell, and more reports of sore throat, runny nose, headaches, sneezing, and fatigue,” David Souleles, MPH, director of the COVID-19 Response Team and director of the Masters in Public Health Program and Practice at the University of California Irvine, told Healthline. “However, it is important to remember if you are experiencing any COVID-19 symptoms to get tested as soon as symptoms appear.”
Vaccinated people are more likely to experience Omicron like a common cold.
However, unvaccinated people and those with compromised immune systems have a higher chance of developing serious illness from COVID-19, even with the typically milder Omicron variant.
“Unvaccinated individuals… tend to have more prolonged and worse symptoms, starting off as cold-like symptoms, but progressing to severe respiratory symptoms, coughing, debilitating body aches, and headaches, difficulty breathing, and — in severe cases — pneumonia, respiratory failure, and even death,” Brown said.
Omicron is the most infectious variant of the coronavirus so far, but it doesn’t seem to be as deadly as prior variants such as Delta.
Researchers say that’s because Omicron tends to stay in the upper respiratory system, rather than settling in the lungs where it can do more damage.
“Studies have shown that Delta particles settle down in the lungs and damage lung tissue much more readily, leading to pneumonia,” said Brown. “Conversely, Omicron tends to settle in the upper airways (nose, throat, and bronchi). Where the virus settles may be one of the main reasons why symptoms differ.”
Both the severity of illness and length of infection appear to be less for Omicron, especially for those vaccinated and boosted, said Brown.
“However, despite some of these symptoms being seemingly less severe, Omicron spreads much more quickly — up to three times faster than Delta,” he said. “That has resulted in higher numbers of individuals being infected and more patients coming to the hospital for evaluation and treatment.”
“To be clear: Omicron patients are overrunning hospitals, signaling that the Omicron variant is not mild to those who are unvaccinated, unboosted, and immunocompromised,” he added.
In addition to spreading more easily among both vaccinated and unvaccinated people, Omicron may also pose an increased risk of reinfection for people who have already had COVID-19.
Jennifer Horney, PhD, founding director and professor of the epidemiology program at the University of Delaware, told Healthline it’s not entirely good news that Omicron spreads more easily but causes milder symptoms than other variants.
“If it does have milder symptoms, how many people will get tested?” she said. “The virus wants to find people to infect, and if people don’t get as sick, the virus will probably spread faster because people are out and about.”
That could get the population closer to herd immunity against COVID-19, but Horney said those gains could be limited by the fact that natural immunity from coronavirus seems to fade relatively quickly.