You are twice as likely to die from coronavirus if you have the infection at the same time as flu, the boss of NHS England has warned.

Sir Simon Stevens said the health service was doing “very well” at expanding uptake of the flu vaccine, hailing the “brilliant work” of GPs.

But he stressed that uptake of the vaccine was “so important given that if you have flu and coronavirus at the same time you are twice as likely to die from coronavirus than you otherwise would”.

Addressing a No.10 Covid briefing, Stevens also warned lockdown sceptics that the the second wave was “fact not speculation” with more than 11,000 patients currently in hospital with the virus.

That would be enough to fill 22 of England’s hospitals, “indisputably” illustrating the challenges facing the health service as England re-enters lockdown.

“Those are facts – those are not projections, forecasts, speculation, those are patients in hospital today,” he told a No.10 press briefing.

“11,000 coronavirus patients that we have got in hospital compares with 3,000 patients that we would typically have in hospital on any one day during a very bad winter flu season, for flu.

“It compares with about 7,000 patients who’d be in hospital today being looked after for cancer.”

Stevens warned that the number of patients in hospital was likely to surge with more than 25,000 new cases recorded on Wednesday, explaining that there is a lag between people getting infected and developing symptoms that lasts around five days.

Following this, two to five more days pass before someone is hospitalised, and then it takes between nine and 19 days before that patient is either discharged or dies.

“Today’s infection is the intensive care order book for a fortnight’s time,” Stevens warned. 

There are currently around 30,000 staff in the health service either off with coronavirus or having to self-isolate which “has an impact” on care, Stevens said as he stressed the importance of lockdown.

“Our success in controlling community transmission of coronavirus also is a force multiplier, to what the NHS itself can then provide in the way of care,” he said.

Boris Johnson meanwhile told the briefing the objective of the lockdown was to “have as normal a Christmas as possible”.

The prime minister said that while many people were “anxious, weary and fed up” the measures were strictly time-limited.

“The advice I have received suggests that four weeks is enough for these measures to make a real impact,” he said.

“These rules will expire and on December 2 we plan to move back to a tiered approach. There is light at the end of the tunnel.

“These are difficult times. While it pains me to have to ask once again once again for so many to give up so much, I know we can get through this.”