What is XFG Covid strain? These are the symptoms to look out for

Covid cases almost doubled last month before rapidly dropping amid the vaccination roll-out.

The UK Health Security Agency (UKHSA) monthly figures show in October a total of 8,518 people contracted Covid, a 40 per cent increase on September which saw 5,201 cases overall.

But weekly data is now showing a decline in cases, with UKHSA recording a drop of more than 300 cases in the week to October 27.

Between 14 September 2026 and 27 September 2026, just 4.2 per cent of cases were found to be a variant of XFG – also known as the Stratus or “American Covid” strain – which was first identified last January and has since spread around the world.

Have Covid cases increased?

A total of 1,847 Covid-19 cases were identified in hospital settings in the seven days up to 27 October, decreasing from 2,151 cases in the previous week, according to the latest UKHSA data.

Although weekly cases have declined, the number of deaths recorded in the week to October 16 increased by 25 per cent to 69 from 55 the previous week.

So far 59.3 per cent of eligible people have had their autumn booster, but data suggests it is having a positive impact on Covid cases.

The dip in cases comes after cases rose steeply in September and October.

In the seven days to September 23, cases rose to 1,364 from 1,061 the previous week.

By the end of September, in the seven days to September 30 cases reached 1,880, the following week cases hit 2,427 before declining.

Cases were still far below their peak in January 2021 when there were more than 20,000 people in hospital, according to UKHSA.

Health officials urged eligible people to get their flu and Covid jabs in October ahead of the winter months when cases typically rise.

What is the XFG covid variant?

The XFG strain or “Stratus” has been in circulation in Europe and North America since the end of 2025.

The World Health Organisation identified it as a mix of earlier variants LF.7 and LP.8.1.2.

Alex Allen, consultant epidemiologist at the UKHSA, said: “While Covid-19 activity has shown some recent increases, cases remain at low levels in the UK.

“UKHSA is monitoring all the data relating to Covid-19 variants in the UK and abroad, and we continue to publish our findings in our regular surveillance reports.”

This winter’s vaccine is specifically designed to protect against this strain and its variants.

What are the symptoms?

Symptoms of the XFG strain are similar to previous variants. It can cause a sore throat, cough, fever and hoarseness.

But in most cases those who show symptoms do not need to take a lateral flow test, the NHS said.

However, the health service has advised those who think they have Covid to avoid contact with other people for five days, or three days for those under 18.

Everyone who tests positive should avoid meeting people with weakened immune systems for 10 days after the day they took the test.