Omicron Variant Found Less Likely To Cause Long COVID Than Delta Variant

Researchers found that the omicron coronavirus variant is less likely to cause long COVID symptoms in infected people compared to those who contracted the delta variant of the disease.

An analysis from King's College London of data from the ZOE COVID Symptom study app was published on June 18 in a letter to the medical journal The Lancet. The findings of the researchers are from the first peer-reviewed study on long COVID risk and the omicron variant.

Long COVID and Virus Variants

NICE guidelines define long COVID as having new or ongoing symptoms four weeks or more after the first signs of the disease. Symptoms of this condition can include fatigue, shortness of breath, loss of concentration, and joint pain. It is known to adversely affect day-to-day activities and can severely limit a person.

Experts found that the odds of suffering from long COVID were between 20% and 50% less during the omicron wave than during the delta wave. The researchers identified 56,003 UK adult cases that first tested positive between Dec. 20, 2021, and Mar. 9, 2022, as per SciTechDaily.

The study compared these cases to 41,361 others that first tested positive between June 1, 2021, and Nov. 27, 2021, when the delta variant was the dominant strain. The results showed that 4.4% of omicron cases resulted in long COVID compared to 10.8% among delta cases.

However, the absolute number of people experiencing long COVID was higher in the omicron period. This phenomenon was due to the vast number of people infected with the omicron variant from December 2021 to February 2022.

According to News Medical, the data that showed the relative odds of long COVID among those infected with relatively recent variants such as delta and omicron is helpful. This is particularly true for health authorities and policy-makers to allocate health resources appropriately.

Lower Risk of Lasting Illness

Kevin McConway, emeritus professor of applied statistics at The Open University, said that the much bigger number of new infections during the omicron wave "entirely trumped" the variant's potential lower risk of long COVID. He noted that people didn't really have a choice about which virus variant they were going to get.

He added that the findings of the study did not reveal what could happen if a different, new variant of the coronavirus was to emerge. The researchers of the study tried to take into account other variables, including how long ago a person had been vaccinated against COVID-19.

However, it was impossible to be certain that the difference between variants caused the difference in long COVID numbers. In a statement, Dr. Claire Steves, the lead researcher, said that the omicron variant appeared substantially less likely to cause long COVID than previous variants.

The medical professional noted that one out of every 23 people who were infected with COVID-19 went on to have symptoms for more than four weeks. Steves said that given the numbers of people affected, it was important to continue to support people at work, at home, and within the NHS, BBC reported.