Long COVID Could Be Half as Likely With Omicron vs. Delta

MONDAY, June 20, 2022 (HealthDay News) -- The Omicron variant is less likely to give you long COVID than a previous strain of the virus, British researchers say.

What was described as the first peer-reviewed report to investigate Omicron and patients' risk of persistent symptoms found 4.4% of Omicron cases resulted in long COVID. That's well below the nearly 11% associated with the Delta variant, which was the dominant strain of SARS-CoV-2 earlier in the pandemic, researchers said.

But because the Omicron variant is far more contagious than Delta, more people get infected with Omicron and, therefore, more experience long COVID, they added.

"We still need to keep providing support for people with long COVID while we try to understand why it occurs and how we can treat it," said lead researcher Claire Steves, a senior clinical lecturer at Kings College London.

Long COVID can include a variety of symptoms and last for weeks, months or, potentially, years, affecting a person's quality of life, according to the U.S. Centers for Disease Control and Prevention. Sometimes the symptoms can go away or come back.

They can include fatigue, fever, malaise, trouble breathing, cough, chest pain, heart palpitations and dizziness. People can also have foggy thinking, depression, anxiety, headaches and sleep problems, as well as loss of smell and taste. Diarrhea, stomach pain, muscle ache, rash and changes in the menstrual cycle are also possible.

For the study, Steves and her colleagues used the U.K.-based ZOE COVID Symptom study app to collect data on 56,000 people infected with the Omicron strain. They were compared with more than 41,000 people infected with the Delta strain.

The upshot: Odds of getting long COVID were 20% to 50% lower with Omicron than Delta. The odds were dependent on a patient's age and time since vaccination.

Infectious disease expert Dr. Marc Siegel, a clinical professor of medicine at NYU Langone Medical Center in New York City, said long COVID is probably more common than realized.

"[Omicron] doesn't cause as much deep lung infections, but it's also true that there's immune protection from the vaccine and previous infections to some extent," he said.

It follows that if cases are less severe, there won't be as much long COVID, said Siegel, who reviewed the findings.

"That's my personal experience," he said. "In my practice, I never see anyone with loss of smell and taste anymore."

Still, Siegel predicts COVID may become a permanent part of the landscape, like the flu.

"We're still seeing disease and hospitalizations, but we're seeing a lot more disease than hospitalizations now," he said. "I think that's where we're heading with this. I can't be sure, but I think we're heading into a semi-permanent phase of persistent disease, but less severe outcomes."

He emphasized that having had COVID doesn't mean you won't get it again, because immunity from the infection appears to be short-lived. And breakthrough cases are possible even if you're vaccinated, though they're likely to be less severe than if you weren't, Siegel said.

"Don't count on prior infection to completely protect you and don't count on a vaccine to completely protect you, but get as much immunity as you can," he said.

It's reassuring to know that Omicron appears to cause fewer long-term symptoms, Siegel said.

"Be aware that Omicron causes fewer long-term symptoms but not zero," he emphasized. "We need to continue to be aware of this virus and to be cautious about it."

The new findings were published online June 18 in The Lancet.

More information

The U.S. Centers for Disease Control and Prevention has more about long COVID.

SOURCES: Claire Steves, PhD, senior clinical lecturer, Kings College, London, England; Marc Siegel, MD, clinical professor, medicine, NYU Langone Medical Center, New York City; The Lancet, June 18, 2022, online