Friday Jun 17, 2022
LONDON: The Omicron variant of coronavirus is less likely to cause long COVID-19 than previous variants, according to the first peer-reviewed study of its kind from the United Kingdom.
Researchers at King's College London, using data from the ZOE COVID Symptom study app, found the odds of developing long COVID-19 after infection were 20% to 50% lower during the Omicron wave in the UK compared to Delta. The figure varied depending on the patient's age and the timing of their last vaccination.
Long COVID-19, which includes prolonged symptoms ranging from fatigue to "brain fog", can be debilitating and continue for weeks or months. It is increasingly being recognised as a public health problem, and researchers have been racing to find out if Omicron presents as big a risk of long COVID-19 as previously dominant variants.
The study from King's is believed to be the first academic research to show Omicron does not present as great a risk of long COVID-19, but that does not mean long COVID-19 patient numbers are dropping, the team said.
While the risk of long COVID-19 was lower during Omicron, more people were infected, so the absolute number now suffering is higher.
"It's good news, but please don't decommission any of your long COVID-19 services," lead researcher Dr Claire Steves told Reuters, appealing to health-service providers.
The UK's Office for National Statistics said in May that 438,000 people in the country have long COVID-19 after Omicron infection, representing 24% of all long COVID-19 patients.
It also said the risk of lingering symptoms after Omicron was lower than with Delta, but only for double-vaccinated people. It found no statistical difference for those who were triple vaccinated.
In King's research, 4.5% of the 56,003 people studied during Omicron's peak, December 2021-March 2022, reported long COVID-19. That compared to 10.8% of 41,361 people during the Delta wave, June-November 2021. It did not compare vaccinated and unvaccinated individuals.
While the study — published in The Lancet journal on Thursday — compared Delta and Omicron, Dr Steves said previous work had showed no substantial difference in long COVID-19 risk between other variants.
More work was needed to establish why Omicron may have a lower long COVID-19 risk, the team added.