Boris Johnson‘s blueprint for lifting lockdown could have factored in indoor mixing sooner and still kept hospital bed occupancy levels at the lowest level they are likely to reach in an inevitable third wave, SAGE modelling has suggested.
The Prime Minister today laid out his ‘one-way road to freedom’ in plans to bring in the Rule of Six and mixing of two households outdoors by the end of March, with indoor socialising set for May 17 at the earliest.
However, one plan suggested by SPI-M, a sub-group of SAGE, suggested people could welcome solo visitors into their homes as early as March 29 while keeping most other factors roughly the same as No10’s plan.
SAGE’s modelling shows a third wave of coronavirus infections and hospital admissions will be inevitable when lockdown rules are loosened, with the numbers of people on wards with Covid approaching levels close to, or higher than, the first wave in the spring of 2020.
In a worst-case scenario, another 150,000 people could die before next summer, government advisers led by a team including ‘Professor Lockdown’ Neil Ferguson warned. Although this figure varies depending on how quickly lockdown ends.
One model warned of another 80,000 deaths between now and next June, if No10 acts too quickly.
The models were different lockdown-lifting scenarios suggested by the Cabinet Office, which scientists then predicted the effects of. The Government does not appear to have opted for any of the oven-ready scenarios in SAGE’s modelling but to have created a hybrid that brings forward some relaxations and pushes others back.
Lifting rules earlier but in a controlled manner could keep the hospitalisations below the first wave peak but bring the third wave forward so that it happens in the summer, when the pressure on the NHS is low, instead of winter.
SAGE modelling presented to the Government found that one-on-one indoor mixing could be brought back at the end of March and the inevitable third wave still kept under control. Graph shows how all lockdown-lifting scenarios eventually lead to a third spike in the number of people in hospital – the green line appears to track closely to Mr Johnson’s plan to lift lockdown, but factored in indoor mixing as soon as March 29. It brings forward the next spike in NHS pressure to the summer, when the NHS is less busy, instead of pushing it back to the winter. Modelling conducted by Imperial researchers
A second modelling scenario confirmed that one-on-one indoor mixing being reintroduced in March (scenario 5a, the green line) could be part of a method that keeps the hospital bed occupancy below the first wave peak. Modelling conducted by a separate Warwick University team
Boris Johnson’s lockdown plan, announced today, appears to track closely to scenario 5, which will likely allow the R rate to surge to 2 or higher by the end of April, but some parts have been pushed back
In a worst-case scenario, another 150,000 people could die before next summer, the government advisers warned. Although this figure varies depending on how quickly lockdown ends. One model warned of another 80,000 deaths between now and next June, if No10 acts too quickly
The blueprint for lifting lockdown, outlined by Mr Johnson today and expected to be eased over March, April, May and June, is expected to see the R rate of the virus rise higher than 2 before the end of April. This rate – which measures how many people each person with coronavirus infects – will be higher than at any point since the very beginning of the pandemic.
But it is hoped that widespread vaccination – more than 17.5million people have been vaccinated already and all adults in the UK are likely to have been offered a jab by the time lockdown is lifted completely – will prevent millions of infections and thousands of hospital admissions and deaths.
Children and teenagers are set to bear the brunt of the third wave, with no vaccination coverage among over-18s and schools likely permanently reopened.
Data published today for the first time suggest that the jabs already being used in Britain – made by Pfizer and AstraZeneca – are already preventing between 85 and 94 per cent of hospital admissions among people who have had them, and Pfizer’s jab may be stopping upwards of 70 per cent of people from becoming infected.
But the Government’s top scientists sounded alarm bells in a briefing with journalists this morning, insisting that the easing of lockdown must be led by ‘data not dates’. Dame Angela McLean, deputy chief scientific adviser, said: ‘One of the things that is very clear is this could go wrong if we go about things the wrong way.’
Gloomy modelling presented to SAGE suggested that another 143,000 Britons could die by July 2022 if No10 releases lockdown restrictions too early.
The analysis presented to SAGE – the Government’s panel of top scientific advisers – took into account several different time-frames for completely easing the draconian restrictions.
The most alarming model took into account placing the nation back into Tier 2/3-style measures on March 29 and then fully lifting lockdown on April 26.
The blueprint – made by ‘Professor Lockdown’ Neil Ferguson and his Imperial team – warned that it could lead to another 154,000 deaths between now and next June.
In comparison, the additional death toll would be kept under six figures if ministers waited until July 16 to ease all restrictions.
Separate modelling was also conducted by Warwick University researchers, which came to similar conclusions.
In his roadmap today Mr Johnson signalled that lockdown is unlikely to be lifted before July, saying the final step of easing restrictions would happen no earlier than June 21.
A model of possible ways to ease out of lockdown, produced by the Imperial College Covid-19 Response Team, put forward the prospect of allowing one-on-one meetings indoors from March 29.
Under this scenario, hospital admissions could be kept below the first wave peak of 20,000 people in hospital with the disease, but the third wave would be brought forward to begin in May or June and rumble on through the summer.
This third wave, however, is inevitable. Under the early mixing rule the peak of the third wave is no higher than in other models, it just comes sooner and appears to last slightly longer. A peak in the summer would be safer for the NHS, which is typically over-stretched even in an average winter.
And the earlier spike that comes as part of a plan dubbed ‘scenario 5’, SPI-M suggested, may develop some herd immunity among younger people spreading the virus over the summer.
The paper, dated February 17, said: ‘Prevalence in scenario 5 (and therefore hospital occupancy) is higher in summer than in the previous scenarios 2 and 3 as the first two steps happen more quickly.
‘This means that fewer people are still susceptible at step 4 [total lifting of lockdown].
‘Tying the timing of the final step to the date at which the whole population have been offered at least one dose, limits the height of the second peak compared to easing restrictions earlier.’
Boris Johnson today unveiled his lockdown exit strategy with rules due to start being lifted from March 8
As well as considering the timing of restrictions being lifted, the modelling also looks at how well the vaccine rollout progresses and how effective the vaccines are at preventing Covid-19.
It assumes that vaccines prevent between 50 and 94 per cent of infections, 50 and 94 per cent of symptomatic cases of Covid, and 70 and 98 per cent of severe cases after two doses.
These may be pessimistic estimates, based on studies that were published today suggesting that the Pfizer jab appeared to be preventing at least 70 per cent of infections among healthcare workers, and both jabs were preventing over 85 per cent of severe Covid cases after just a single dose.
The Imperial College model suggested that if vaccines were at the low end of effectiveness and lockdown was lifted completely in April, there could be another 146,000 deaths before July 2022. This could be kept down to 94,000 deaths if lockdown were reduced more gradually up to a total relaxation in July.
Equally, if the vaccine rollout went slower than its current pace but the jabs were highly effective, as expected, deaths would be between 43,000 for the later end to lockdown up to 92,000 with the early lifting.
Professor Ferguson’s team warned: ‘Due to eligibility and vaccine hesitancy, vaccination alone will not be sufficient to keep the epidemic under control. [Lockdown rules] must be lifted slowly and cautiously to minimise the number of deaths and prevent high hospital occupancy, with some baseline [rules] remaining in place (and adhered to) throughout 2021 and beyond…
‘Relaxing too quickly will result in peak hospital occupancy considerably higher than the current wave and substantial additional deaths. This holds regardless of vaccine efficacy, rollout, adherence to baseline [restrictions], and impact of seasonality.’
The paper suggested that even a high-speed vaccine rollout reaching 3.2million doses per week – 2.5m were administered last week – may only lead to two thirds of the country developing immunity by the middle of summer.
Out of 23,324 health workers in the study, 89 per cent were vaccinated by February 5. There were 977 cases of coronavirus recorded in people before they were vaccinated, compared to 71 among people who were three weeks post-vaccination, PHE’s Dr Susan Hopkins said today
The Scottish study showed that both vaccines offer a high level of protection against being hospitalised with Covid from just two weeks after a single dose, with the protection kicking in only a week after injection. There were not enough data to compare the two, the scientists said, although AstraZeneca’s appears to work better in the early stages
In a ray of hope for Britain’s lockdown-easing plans, results showed the jabs slashed the risk of hospital admission from Covid by up to 85 and 94 per cent, respectively, four weeks after the first dose. The graph above shows how the vaccine worked in different age groups
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