Omicron less likely to cause long COVID than delta: study

The omicron variant of the coronavirus is substantially less likely than the earlier delta variant to cause symptoms of long COVID-19, according to a new study.  

The study from researchers in the United Kingdom published in The Lancet finds that 4.5 percent of omicron cases resulted in long COVID, compared to 10.8 percent of delta cases.  

While on one hand it is good news that the currently circulating omicron variant is less likely to cause long COVID than the earlier delta variant, the study also shows there still is a significant chance of getting long COVID, even with omicron.  

“The Omicron variant appears substantially less likely to cause Long-COVID than previous variants but still 1 in 23 people who catch COVID-19 go on to have symptoms for more than four weeks,” Claire Steves, the study’s lead author and a researcher at King’s College London, said in a statement. “Given the numbers of people affected it’s important that we continue to support them at work, at home and within the [health system].” 

In addition, because the omicron variant spreads more easily and infects more people, the total number of long COVID cases was actually higher during the omicron period, the study found. For each individual, though, the odds of getting long COVID are lower.  

Long COVID symptoms can linger for weeks or months after the initial infection, and include fatigue and difficulty concentrating. There is still not a clear understanding of what exactly causes the lingering symptoms.  

The new study in The Lancet helps to put some numbers on the likelihood. It examined over 50,000 omicron cases and over 40,000 delta cases.  

The potential for lingering symptoms is a major remaining concern with COVID-19, given that vaccines, booster shots and treatments have helped to greatly reduce the risk of death.  

“Omicron appears to cause less severe acute illness than previous variants, at least in vaccinated populations,” the study states. “However, the potential for large numbers of people to experience long-term symptoms is a major concern, and health and workforce planners need information urgently to appropriately scale resource allocation.”