By Carolyn Crist

June 17, 2022 — The Omicron variant of the coronavirus poses about half the risk of long COVID as the Delta variant, according to a new study published in The Lancet.

At the same time, about 5% of people who contract Omicron still experience symptoms such as brain fog, fatigue, headaches, heart problems, and other health issues at least a month after getting infected. The study is considered one of the first large-scale reports about the long-term risks of Omicron.

“The basic question that we’re trying to answer is: ‘Is long COVID as common … in the Delta period [as it is] in the Omicron period?” Claire Steves, one of the study authors and a genetic epidemiologist at King’s College London, told NPR.

“What’s the risk of going on to get long COVID, given the different variants?” she said.

Steves and colleagues have been tracking thousands of people who tested positive for COVID-19 to determine the risks of long COVID with different variants. They compared more than 56,000 people in the U.K. who got Omicron between December 2021 to March 2022 with more than 41,000 people in the U.K. who caught Delta between June 2021 and November 2021.

The patients tracked their symptoms using the COVID Symptom Study app. Those who caught Omicron were about half as likely as those who caught Delta to still experience health problems a month later. The chance of developing long COVID from Omicron was 4.5% compared with 10.8% from Delta.

The reduced risk is “great news,” Steves said, especially because Omicron is so contagious that many people have been infected quickly. If the risk of contracting long COVID were the same as the Delta variant or higher, the number of people with long COVID would have exploded, she said.

But the lower risk doesn’t mean people shouldn’t worry about long COVID, she warned.

“The caveat is that the Omicron variant has spread very rapidly through our populations, and therefore a very much larger number of people have been affected,” Steves said. “So, the overall absolute number of people who are set to go on to get long COVID, sadly, is set to rise.”

The study didn’t address why Omicron carries a lower risk of long COVID, though Steves said it makes sense because the variant also tends to have a lower risk of making people severely ill.

Long COVID experts told NPR that future studies should confirm the data in medical clinics, and the findings should inform public health measures.

“We’re saying, you know: ‘You can take off your masks in airplanes. You don’t need to be vaccinated anymore to enter a restaurant.’ All of these policy decisions are going to increase the likelihood that people get infected with COVID, while there’s still a 5% chance of severe chronic illness,” David Putrino, PhD, who treats long COVID patients at Mount Sinai in New York, told NPR.

“That’s short-sighted and going to create a lot of long-term disability that did not need to exist,” he said.