British researchers have discovered the Omicron variant of the Covid-19 virus is less likely to cause long Covid.
Among those who have caught the deadly coronavirus since its emergence in 2020, a significant percentage have experienced longer-term symptoms such as intense fatigue, shortness of breath, brain fog, and other health problems.
However, last winter's milder but very infectious Omicron variant is less likely to have a lingering effect, according to scientists from King's College London.
They looked at data from nearly 100,000 people who logged their Covid-19 symptoms on an app and found that just over four per cent of those infected during the Omicron wave had logged what are typically described as long Covid symptoms. In comparison, 10 per cent of those infected in the preceding Delta wave reported long Covid symptoms.
Lead researcher Dr Claire Steves said: "The Omicron variant appears substantially less likely to cause long Covid than previous variants - but still, one out of every 23 people who catches Covid-19 goes on to have symptoms for more than four weeks."
However, far more people were infected during the Omicron wave so the raw total was higher.
Kevin McConway, emeritus professor of applied statistics at The Open University, said that the larger number of infections during the Omicron wave "entirely trumped" the lower risk for individuals in terms of public policy.
"Anyway, you don't really have any choice about which virus variant you might be infected with," he said. "What's more, nothing in these findings tells us what might happen with a different new variant, in terms of long Covid risk."
They advise that public policy should still account for long Covid even if the risk to infected individuals is reduced. Officials estimate long Covid has affected at least two million people in the UK.