Many people have used the tests during the Christmas period to determine whether it’s safe to visit family and friends as cases of the Omicron variant continue to surge

Brits with cold symptoms should take additional measures when checking for Covid with a lateral flow test, an expert has warned.

Over the festive period people have been using the test to gauge whether it’s safe to visit family and friends for Christmas celebrations.

It comes as the UK continues its battle with the Omicron variant, which accounted for a large chunk of the record 320,000 new cases reported between Christmas Eve and Boxing Day.

Many of the mutation’s symptoms are identical to those suffered during a nasty common cold – including headaches, a sore throat and a runny nose, Liverpool Echo reports.

But Professor Jennifer Rohn, a cell biologist at University College London, warned that a negative lateral flow test may not produce accurate results if you’re suffering with a cold.

Some of the rapid lateral flow tests ask only for a nose swab – but the doctor advises people with symptoms to add in a throat swab as an additional precaution.

She said: “Well, there it is. Today, with the “wrong” (i.e. cold) symptoms and after a string of negative LFTs, I finally took Twitter advice and swabbed my throat as well as my nose (no mean feat with that diddly stick).

“If you think you might have covid, consider adding the throat sample.”

According to Wales Online, a professor of epidemiology at Harvard University claimed the throat swab improves chances of picking up the virus.

Dr Michael Mina said: “Symptoms are starting very early with omicron.

“This means that there is a chance the virus isn’t yet growing in the nose when you first test [as the] virus may start further down.

“Throat swab + nasal may improve chances a swab picks up virus.”

Yesterday, walk-in PCR tests couldn’t be booked in England due to “high demand”.

Appointments were unavailable over the course of a few hours in every region of the country.

Some were available to book in Northern Ireland, Scotland and Wales.

Though there were no in-person slots available, Brits could order a test to be completed at home.

Hours later, booking were back online, with the UK Health and Security Agency saying the reduced availability was just “temporary”.

In a major ramp up of testing in mid-December, the UKHSA announced that pharmacies now have access to 10.5million lateral flow tests each week.

PCR booking slots also increased significantly, with 100,000 per day apparently available after December 16.

The UKHSA was also securing hundreds of millions more LFD tests and upping PCR lab testing to 150,000 daily.

As of yesterday, the UK had recorded 320,000 new Covid cases over the three days of Christmas.

Those figures include the daily numbers that would normally have been published on Christmas Day and Boxing Day, but the statistics for today do not yet include Northern Ireland or Scotland – and do not include Wales, except for 5,000 cases reported on Boxing Day.

The data for England was as follows: 113,628 new cases on Christmas Day, 103,558 new cases on Boxing Day and 98,515 new cases on December 27.

The Christmas Day figure for England was the highest on record since the pandemic began – followed by 107,055 reported on December 23 and 105,069 on Christmas Eve, according to NHS England.

An additional 5,335 new cases were confirmed in Wales on Boxing Day – a figure included in the statistics published today.

Figures from Scotland confirmed yesterday showed there were 8,252 new cases on December 25, 11,030 on December 26 and 10,562 on December 27 – these, however, have not been included in the 320,000 UK total.

These are record daily totals recorded for the nation since reporting on Covid-19 data began in March 2020.