An immunologist has warned the new strain of Covid could be causing different symptoms - including one that emerges during the night.
Omicron BA.5 is a highly-contagious subvariant causing concern as it contributes to a fresh wave of infections around the globe, including the UK.
Scientists have been finding differences with previous strains, including the ability to reinfect people within weeks of having Covid.
A leading immunologist has now suggested it could be causing a new symptom among patients.
“One extra symptom from BA.5 I saw this morning is night sweats,” Professor Luke O’Neill from Trinity College Dublin told a Irish radio station earlier this week.
“Isn’t that strange?” he added.
BA.5 is driving a surge in cases in a number of countries along with BA.4, including across Europe and in Australia. It also became the dominant variant in the US this week.
“The disease is slightly different because the virus has changed,” Prof O’Neill told Newstalk on Thursday.
He added: “There is some immunity to it - obviously with the T-cells and so on - and that mix of your immune system and the virus being slightly different might give rise to a slightly different diease, strangely enough night sweats being a feature.
“But very importantly, if you are vaccinated and you’re boosted, it doesn’t progress into severe disease is the message to keep reminding people.”
BA.5 was first discovered in South Africa in February, one month after BA.4 was identified in the same country. Both have since spread around the world and sparked concern over a resurgence of Covid infections.
It comes as Covid cases in the UK have risen by nearly 20 per cent, according to new estimates, with around 2.7 million people infected last week.
The increase continues to be driven by the Omicron sub-variants BA.4 and BA.5, said the Office for National Statistics, whose latest data show that 1 in 25 people in England had Covid in the week ending 29 June.
This equates to 2.7 million infections — up 18 per cent from 2.3 million in the previous week.
This is the highest estimate since late April, but is still below the record high of 4.9 million, which was reached at the end of March.
