Professor Sir Jeremy Farrar, a member of the Scientific Advisory Group for Emergencies (Sage) and director of the Wellcome Trust, appeared to throw cold water on Boris Johnson’s hope for a ‘significant return to normality’ by the end of the year.

He told the Commons Health and Social Care Select Committee: ‘Things will not be done by Christmas. This infection is not going away, it’s now a human endemic infection.

‘Even, actually, if we have a vaccine or very good treatments, humanity will still be living with this virus for very many, many years to come.’

Sir Jeremy insisted ‘we need to keep the urgency in place in June, July and August’, adding: ‘We need to move now to a consistent long-term approach to this. Because humanity will be living with this infection for decades to come.’

He said June, July and August were a ‘crucial phase’ in the battle to prevent a second wave of Covid-19.

Sir Jeremy told the committee: ‘If we have any sense of complacency of “this is behind us”, then we will undoubtedly have a second wave, and we could easily be in the same situation again.

‘The lockdowns have made an enormous difference to the community transmission – they’ve done nothing to change the fundamentals of the virus.

‘It remains as infectious as at the end of December, it has the same clinical syndrome, it kills the same number of people.

‘And as soon as the lockdowns ease, if we don’t have mechanisms to change the fundamentals – that means diagnostics, testing, treatments and vaccines – then this will come back, and it’ll come back in winter when all the other respiratory (diseases do).’

He added: ‘If we don’t have things in place by the beginning of September when schools restart, we will face a very, very difficult winter.’

Another expert, Professor Sir John Bell, of the University of Oxford, told MPs ‘the reality is that this pathogen is here forever’, adding that ‘it isn’t going anywhere’.

He said: ‘This is going to come and go, and we’re going to get winters where we get a lot of this virus back in action.

‘The vaccine is unlikely to have a durable effect that’ll last for a very long time, so we’re going to have to have a continual cycle of vaccinations, and then more disease, and more vaccinations and more disease.

‘So I think the idea that we’re going to eliminate it across the population, that’s just not realistic.’