The NHS could have to deliver its “biggest ever” flu immunisation programme this winter as it prepares for a second wave of coronavirus, its chief executive warned.

Sir Simon Stevens told BBC’s Andrew Marr Show on Sunday that it was “entirely possible” there could be another increase in Covid-19 cases in the UK over the winter months.

And he warned it was still not known whether a vaccine would be available in time.

Asked if the NHS was preparing for a second wave, Sir Simon said: “Yes, it is entirely possible there will be.

“Particularly if it is co-existent with the flu.

“And the risk is many of the symptoms are interchangeable.

“So one of the things we need is a very rigorous NHS testing and tracing service available.

“The ability to give early warnings to hospitals where there are those local increases and I think we are going to need the biggest-ever flu immunisation season we have ever had.”

Sir Simon said there were more than 20 research groups working on a vaccine, with some suggesting one could be available between September and December.

“But there is still quite considerable uncertainty as to how you would administer it, would it be two doses or one?

“Do you have to take it separately from the flu jab?

“How long does the immunity last?

“But clearly that would be a major gain were we able to get it.”

Sir Simon said there could be “very significant” extra costs to the NHS later this year around the flu vaccination campaign, personal protective equipment (PPE) and sustaining extra hospital beds.

Asked how much it could cost, he said: “That is a dialogue we are having, but all the signs are that we will get the support we need.”

Sir Simon also spoke about calls for pay increases for NHS staff after unions representing more than 1.3 million nurses, cleaners and paramedics wrote to the Chancellor and Prime Minister about the issue.

He said while he wanted to see frontline health service staff “properly rewarded” for their work, it would be a decision for the Government.

Speaking on the 72nd anniversary of the NHS, Sir Simon said he also wanted to see plans put in place to adequately fund the adult social care sector within a year.

He said the pandemic had shone a “very harsh spotlight” on the “resilience” of the social care system.

“If any good is to come from this,” Sir Simon said, “in my opinion, we must use this to resolve once and for all to actually properly resource and reform the way in which social care works in this country.

“The reality is that after at least two decades of talking about it, we do not have a fair and properly resourced adult social care system with a proper set of workforce supports.”

He added: “I would hope by the time we are sitting down this time next year on the 73rd birthday of the NHS that we have actually, as a country, been able to decisively answer the question of how are we going to fund and provide high-quality social care for my parents’ generation.”