The second wave of Covid-19 in the UK appears to have peaked. The daily number of cases continues to fall, and the number of people admitted to hospital with the virus is also showing signs of improvement. On Tuesday (26 January), 22,195 cases were reported, down around a quarter from the week before.
The number of people dying within 28 days of being infected is still rising, due to the time between becoming infected and succumbing to the disease, but soon that figure will also start to decrease.
This is good news for the UK: it shows that the current lockdown is working. The national R number is now estimated to likely be below 1, meaning fewer people are catching the disease than the number of people that currently have it. You can get the full picture of Covid-19 rates in your local area using our local tracker here.
The more worrying news is the government’s possible reaction to the improving figures. Tory back-bench MPs have been pressuring the Prime Minister to ease the lockdown, and Boris Johnson told reporters this week that he was “looking at the potential of relaxing some measures” by mid-February. The Prime Minister said today that he hopes schools can open on 8 March.
Research teams across the country have attempted to model the effects of easing restrictions early. Among them are researchers at the University of Warwick, who consider the impact of restrictions reverting to those in place in September 2020. A pre-print of a paper they have written, although it has not yet been peer-reviewed, suggests that under some scenarios relaxing restrictions early could lead to tens of thousands of extra deaths. The different scenarios are based on different assumptions about the extent to which vaccines block transmission, as well as how many people take the vaccine.
Vaccine uptake is key
According to the government’s vaccine roll-out plan, only care home residents, front-line health workers and those aged 70 and over are expected to have been offered their first dose by mid-February. Not everyone offered a jab will choose to take it: the latest figures from YouGov suggest an uptake of 81 per cent. The University of Warwick pre-print assumed a 95 per cent uptake in care homes and 75 per cent elsewhere as the default scenario. Increasing this latter figure to 85 per cent in those above 50 (the “optimistic scenario”) leads to between 5,000 and 25,000 fewer deaths if restrictions are eased in mid-February.
Mark Woolhouse, professor of infectious disease epidemiology at the University of Edinburgh, has also been modelling the reopening. He said: “Coverage here is absolutely key. If it were 90 per cent – which is pretty good for a vaccination programme – that still leaves about one million of the most vulnerable unprotected.”
It is also worth remembering that the vaccines themselves don’t have 100 per cent efficacy, especially after one dose. Public Health England has estimated the Pfizer vaccine to be 89 per cent effective between 15 and 21 days after the first dose, and the Oxford vaccine is expected to be 73 per cent effective 22 days after the first dose. Recent early reports from Israel have suggested a single dose of Pfizer vaccine appeared “less effective” than previously thought, although that data is preliminary and the report has been questioned.
The effect of vaccines on transmission is crucial
The largest unanswered question isn’t how effective vaccines are at preventing disease, but their effect on infection and asymptomatic transmission. The University of Warwick pre-print suggests that partially easing restrictions to September levels in mid-February could lead to a total of around 18,000 Covid-19 deaths after January – assuming the vaccines reduce transmission by 75 per cent. That figure rises to around 22,000 if transmission is reduced by half, and around 35,000 deaths for a 25 per cent reduction.
At least 10,000 deaths will occur due to the slow decline of the virus even if restrictions are kept at current levels until July – but the earlier that restrictions are lifted, the higher that figure becomes. The speed at which restrictions are eased also has an effect. Professor Keeling said: “We predict that a rapid relaxation of controls will lead to a huge wave of infection, with many associated hospitalisations and deaths.
“A more gradual relaxation of controls is far less risky, partly because you can always roll back if things look bad.”
Since mid-December, NHS England figures show that as hospitalisations and inpatient Covid-19 diagnoses have risen, so has the proportion of under-65s. Approximately 61 per cent of admissions and diagnoses in the week to 15 January were individuals under the age of 65, compared to 47 per cent a month earlier. Since December, 60 per cent of people admitted to intensive care have been under the age of 60, and a quarter have been under the age of 51. These figures will only rise if restrictions are released while the virus is still in mass circulation.
Vaccination is not a quick route out of restrictions. The extent to which they can be relaxed – and when – depends on the number of people that can be protected. That in turn depends on how effective the vaccines are at reducing transmission, and how many people choose to take them.
We need more data on both the uptake and effectiveness of the vaccines. Currently, there are too many unknowns. But all the models point in the same direction: an easing of restrictions in February could cause a pronounced third wave that is as bad, or maybe even worse, than the peak we have just passed.
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