Scientists say people have been infected with a new Covid variant that could soon gain popularity and become the dominant variant.

The XEC variant was identified in Germany in June and has since been found in the UK, US, Denmark and several other countries. users on X, formerly known as Twitter.

There are some new mutations that could allow the disease to spread this fall, but experts say vaccines can still help prevent severe cases.

For people at higher risk of becoming seriously ill from Covid-19, the NHS is offering a free booster jab.

The vaccines have been updated to better match recent variants, but not XEC, which emerged from earlier Omikron subvariants.

Prof Francois Balloux, director of the Genetics Institute at University College London, told BBC News that while XEC has a “slight transmission advantage” over other recent Covid variants, vaccines should still provide good protection.

He says it is possible that XEC will become the dominant subvariant in winter.

Eric Topol, director of the Scripps Research Translational Institute in California, says XEC is “just getting started.”

“And it’s going to take weeks, a couple of months before it really catches on and creates a wave,” he told the LA Times.

“XEC is definitely taking the lead.

“That does indeed seem to be the next variant.

“But it will take months before we reach a high level.”

The symptoms are thought to be the same as those of a cold or flu:

• a high temperature
• pain
• fatigue
• cough or sore throat

Most people feel better within a few weeks of Covid, but recovery can take longer.

There is ‘strong growth’ of XEC in Denmark and Germany, says Covid data analyst Mike Honey says on X.

There is much less routine testing than before, making it difficult to know how much Covid is present.

According to the UK Health Security Agency (UKHSA), it is normal for viruses to mutate and change.

People eligible for a free booster vaccination include:

• adults aged 65 and over
• who live in a nursing home for the elderly
• persons over six months of age in a clinical risk group
• some frontline workers in the NHS, care homes and social care

The most important vaccination campaign against flu and Covid will begin in October, although some may be able to get their vaccination earlier.

Dr Gayatri Amirthalingam, deputy director of UKHSA, said: “It is normal and expected for viruses to change genetically over time. UKHSA continues to monitor all available information regarding emerging Covid variants in the UK and internationally and publishes our data regularly.

“Vaccination offers the best protection against serious illness from COVID-19, and we urge those who have been contacted by the NHS to come forward to get their autumn vaccine.”