Delaying lockdown beyond July 19 will not reduce the number of Covid deaths and could potentially lead to a worse peak in winter, Professor Chris Whitty warned last night.
The Chief Medical Officer acknowledged that while some restrictions would always be better than none in terms of containing Covid, at some point they have to be released for the sake of the economy and wider health.
Professor Whitty revealed he believed 'quite strongly' that there are many benefits to unlocking now rather than waiting until autumn - which some have suggested could buy No10 time to get every adult fully vaccinated.
It would get the big bang of Covid infections and hospital admissions — expected when social distancing comes to an end — out of the way in summer when the NHS is less busy.
'At a certain point, you move to the situation where instead of actually averting hospitalisations and deaths, you move over to just delaying them,' the CMO told a Downing Street press conference last night.
'So you're not actually changing the number of people who will go to hospital or die, you may change when they happen.
'There is quite a strong view by many people, including myself actually, that going in the summer has some advantages, all other things being equal, to opening up into the autumn when schools are going back and when we're heading into the winter period when the NHS tends to be under greatest pressure for many other reasons.'
The comments come on the back of modelling from prominent SAGE member 'Professor Lockdown' Neil Ferguson that suggested late July was an apparent 'sweet spot' for releasing curbs.
His team at Imperial College London found delaying the original June 21 date until later this month likely prevented thousands of deaths. Delaying them until autumn or winter could result in more fatalities.
Even though more people would be vaccinated, scientists believe releasing curbs in winter would cause a bigger spike because people spend more time indoors and other respiratory viruses are rife. The NHS will also be grappling with normal winter pressures.
Professor Whitty, Professor Ferguson, who was instrumental in Britain's first lockdown last spring, and Sir Patrick Vallance, the chief scientific adviser, are both believed to be in the 'if not now, then when' camp.
During a round of interviews this morning, the normally cautious Professor Ferguson said pressing ahead with July was 'justifiable' and revealed he was 'reasonably optimistic'.
HOSPITAL ADMISSIONS: Modelling by Professor Neil Ferguson's team at Imperial College London found that delaying Freedom Day until December (shown in green) to let all adults get double-vaccinated would push the peak in Covid hospital admissions further into winter, rather than reducing the number of admissions completely. The yellow line shows the effect on admissions if the unlocking was to go ahead in late July, with hospitalisations peaking in summer and plummeting by winter. Releasing curbs in June (blue) or early July (red) would have led to a bigger peak in summer, which is why the decision was made to push the original June 21 Freedom Day back by a month
COVID INPATIENTS: The same was true for hospital occupancy levels and, although the graphs don't explicitly show it, the team at Imperial said in some scenarios, delaying the unlocking until December could lead to more deaths. In their paper, they write: 'In some of our modelled scenarios, this long delay paradoxically leads to more total deaths since the third wave would be pushed into the winter, when transmission may be higher because of seasonality and increased indoors interactions, and when an increased proportion of individuals may have lost protection from prior infection'
He made the comments at a Downing Street press conference tonight, where Boris Johnson confirmed that most social distancing rules will no longer be mandatory from July 19
Speaking about last night's announcement, Professor Ferguson told the Today Programme: 'This is a slight gamble, it's a slight experiment at the moment, and I think it's justifiable and I'm reasonable optimistic, but policy will have to remain flexible.'
He said the vaccines' effect on hospitalisations and deaths gave him confidence that the NHS will be able to cope despite rising cases, but warned that if infections continue to grow exponentially then hospitals could be pushed to the brink.
The Government scientific adviser added: 'At the peak of the second wave 50,000 cases would translate into something like 500 deaths, but that's going to be much lower this time, more like 50 or so.
'The challenge is, there's still the potential of getting very large numbers of cases and so if we get very high numbers of cases a day, 150,000 or 200,000 it could still cause some pressure to the health system.