Researches in the UK have said that headache, sore throat, and runny nose are the most commonly reported symptoms linked to Covid-19 infections from the Delta variant which was first reported in India.

Professor Tim Spector, who runs Zoe Covid Symptom study, has suggested that being infected by the Delta variant can feel "more like a bad cold" for younger people, reports the BBC. As a result, they might not feel very ill but can put others at risk.

According to the National Health Services in the UK, the classic Covid-19 symptoms that people should look out for are: cough, fever and loss of or change in smell or taste.

However, Professor Spector claims -- based on the data the Zoe Covid Symptom study team has been receiving from thousands of people who have logged their symptoms in their app -- the above symptoms are less common now.

"Since the start of May, we have been looking at the top symptoms in the app users -- and they are not the same as they were," he says.

The changes appear to be linked to the rising Delta variant, which currently accounts for 90% of Covid-19 cases in the UK.

According to published data between May 23 and June 5, cases of the Delta variant are higher and increasing faster within the unvaccinated population in the UK. Cases have experienced a significant uptick within the 20-29 year-old age group, with the 0-19 year-old age group following closely behind, reports The Guardian.

The soaring numbers are probably rooted in the higher transmission rate of the Delta variant and fatigue around social distancing.

"People might think they've just got some sort of seasonal cold, and they still go out to parties, and they might spread it around to six other people. We think this is fuelling a lot of the problem," the BBC report quoted Professor Spector.