Research finds COVID-19 symptom severity differs by variant

The Omicron variant is making up 75 percent of cases making it a more dominant COVID-19 strain currently. Credit: Mackenzie Shanklin | Photo Editor

COVID-19 symptoms differ depending on the variant at play, affecting the severity of a case, according to the Centers for Disease Control and Prevention.

With the ongoing addition of new COVID-19 variations, Ohio State experts have offered their take on the differences in the severity of symptoms between the omicron, delta and alpha variants.

The dominant COVID-19 strain in the U.S. is the omicron variant, making up 75 percent of cases, according to the CDC. Dr. Nicholas Kman, an emergency medicine physician at the Wexner Medical Center at Ohio State, said omicron shows milder symptoms than the other variants.

“[Omicron] has many more mutations than delta, and because of those mutations, it’s actually better at evading the vaccines, but it’s not as good at getting into the lungs and causing pneumonia and respiratory failure,” Kman said. 

Kman said this is why fewer patients require ventilators with the omicron variant.

Common COVID-19 symptoms include fever, dry cough, fatigue, loss of taste and smell, shortness of breath, muscle aches, headaches, runny nose, nausea, diarrhea and sore throat, according to the CDC. 

Ohio State currently has a COVID-19 positivity rate of less than 1 percent and a vaccination rate of 93.3 percent, according to the Ohio State COVID-19 dashboard.

Kman said omicron is in its decline and, although still contagious, the mild symptoms help people get over illness quicker while also moving the needle toward natural immunity in America. However, he said there is still uncertainty around new COVID-19 variants, including branches of omicron like BA.2.

“We know that omicron has a sublineage called BA.2,” Kman said. “Now, right now, it seems like it behaves a lot like omicron, but I think we always need to kind of be on the ready for, ‘What’s the next curveball we’re going to get?’ ”

BA.2 is a sublineage of the omicron variant that gives patients mild and, in some cases, completely unnoticeable symptoms, but it also has been found to be more contagious than the original strain of omicron.

Dr. Nora Colburn, associate medical director of Clinical Epidemiology at the medical center, said in an email that patients who have received a COVID-19 vaccine and booster shot tend to experience milder symptoms than those who have not been vaccinated.

Kman said omicron is more likely to cause symptoms that are not lung-related.

“That’s why we see people with sore throat, runny nose, head congestion, headache — because omicron tends to target those cells over the cells in the lungs,” Kman said.

Colburn said individuals should stay up to date with COVID-19 vaccinations, and if people start experiencing symptoms, they should get tested and self-isolate.

For more information about COVID-19, visit the CDC website.