An immunologist has cautioned that the new strain of Covid-19 could cause a variety of symptoms, including one that appears at night.

Omicron BA.5 is a highly contagious subvariant that is causing concern as it contributes to a new wave of infections all over the world.

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 an Irish radio station in mid-July.

“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 has also become the dominant variant in the US.

“The disease is slightly different because the virus has changed,” Professor O’Neill told Newstalk.

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.”