Next Monday's lockdown easing will trigger the start of another wave of Covid, SAGE has warned, but it won't be anywhere near as bad as the ones in spring or winter 2020.
In more than 100 pages of files published tonight as Boris Johnson announced social distancing would become optional from May 17, scientists said they were 'more optimistic' about the reopening than earlier in the year.
The better-than-expected vaccine rollout and warmer weather would have Covid on the back foot and keep hospital admissions and deaths much lower than in Britain's first and second waves. Even the worst case scenario submitted by Warwick University experts suggests hospital occupancy might only reach half of its January high.
But SPI-M, a sub-group of SAGE that contains disease modelling experts such as Neil Ferguson, Graham Medley, John Edmunds and Steven Riley, said 'it is likely that Step 3 will lead to R greater than 1 in England'.
This means the rate of spread will be pushed into a continuously increasing state, with everyone catching the virus infecting one or more people.
Due to widespread vaccination of the people most likely to get severely ill or die, however: 'Any resurgence in hospital admissions and deaths following Step 3 of the Roadmap alone is highly unlikely to put unsustainable pressure on the NHS,' they added.
Top-line estimates shown to the Government by SPI-M suggest that following the May 17 unlocking and then opening up society completely in June would likely lead to a maximum of 55,000 hospital admissions over the next year – compared to 464,000 since the start of the pandemic – and to 11,200 more people dying by September 2021.
Prime Minister Boris Johnson has already indicated that more disease and death is inevitable, saying in February there was 'no credible route to zero Covid' and adding: 'Whenever we ease the lockdown – whether it’s today or in six or nine months – we’ve got to be realistic and accept that there will be more infections, more hospitalisations and therefore, sadly, more deaths, just as there are every year with flu.'
The PM tonight confirmed next Monday's softening of the rules would go ahead as England announced zero new Covid deaths for the first time July 30, and there were another 2,357 coronavirus cases and four deaths across the UK. The Covid alert level was downgraded from four to three, suggesting the virus is 'in general circulation'.
SPI-M said in its report, presented to SAGE last Wednesday, May 5: 'Modelling presented in these central scenarios is more optimistic than those in SPI-M's previous Roadmap modelling.
'This is primarily due to recent evidence that vaccines significantly reduce onwards transmission from people who have been vaccinated but nevertheless become infected then symptomatic.
'This suggests that if baseline policies to reduce transmission are kept in place at the end of the Roadmap, behaviour does not return to pre-pandemic levels, and vaccine roll out progresses, there is an opportunity to keep the next resurgence very small.'
The report does not take into account the possibility of a new dominant variant that can escape vaccine immunity or spread faster than the Kent strain, and works off the basis that the situation in the UK is approximately as it is now while measures are released.
Scientists add that 'seasonality' could mean there are fewer cases over the summer – as was seen last year – and the next wave is pushed back to autumn and winter. They estimate transmission is around 10-20 per cent more likely in February than in August in the same outbreak situation.
This is because UV light is known to kill the virus and people spend more time outdoors, where transmission is significantly less common because people don't breathe the same air as much.