The UK went into lockdown this week after terrible coronavirus data showed the virus spreading rapidly across the country, threatening to overwhelm hospitals.
The new, more transmissible, B.1.1.7 strain of Covid-19 has created a bleak outlook, with an Office for National Statistics random sample of the population last week showing that one in 30 Londoners had the virus.
Almost no parts of England are now free of coronavirus, with only 10 of the 6,791 “middle layer super output” areas into which the ONS divides the country — localities of roughly 7,000 people — having fewer than three positive cases in the week up to New Year’s Eve. The rate of positive test results has been rising rapidly.
Amid these dark clouds, there are some silver linings in the coronavirus data, which provide signs that the lockdown can contribute to reducing case numbers and begin to alleviate pressure on the health service.
The worst-hit areas are no longer deteriorating
Across England the average rate of positive Covid-19 cases per 100,000 people rose from 399 in the week to Christmas Eve to 534 in the week to New Year’s Eve. The rate of positive cases increased in 78 per cent of the 6,971 ONS areas.
But in the 423 local areas where the case rate had been above 1,000 per 100,000 in the week before Christmas, it grew further in only half those areas and declined in the other half. The average rate in these areas dropped slightly.
In the local authority of Medway in Kent, which includes the towns of Rochester and Chatham, the rate stopped growing exponentially once it hit this threshold.
No one is certain why the case rate in the hardest-hit areas has levelled off or whether this will continue, but the figures raise the possibility that when the prevalence of the virus rises to very high levels in local areas, people hunker down, limiting further exponential increase. There is no sign yet that cases have dropped to low levels in these areas.
Random testing suggests some easing in capital
The ONS finding that one in 30 people randomly tested in London was positive came as a shock this week and added to the government’s argument for imposing a strict lockdown.
But alongside signs of symptomatic cases no longer rising in the worst-hit areas such as north Kent, random testing by the ONS also showed a levelling-off in London, although the statistics office cautioned that strong conclusions should not be drawn from the most recent data.
Chris Whitty, the chief medical officer for England, also cautioned about over-interpreting the figures but said: “In some of the areas where [the new variant] took off to the highest level and tier 4 was brought in during a period when schools were closed, there may be some early indications of some levelling off”.
If these trends continue, it means that school closures alongside the lockdown rules would be sufficient to stop the caseload rising, although any benefit to hospitals or deaths would still be weeks away.
Cases rising more slowly among over-60s
Hospitals are under severe strain across the UK — as demonstrated by the Covid-19 alert level being raised to the maximum, five, on Monday. This means that “without further action there is a material risk of the NHS in several areas being overwhelmed over the next 21 days”.
Hospitalisations and deaths are extremely closely linked to age and the situation would be worse if older people had the same prevalence of the virus as those under 60. Although cases among older people have been rising quickly, the total for over-60s was 57 per cent that of the number for under-60s in the week before New Year’s Eve.
Among 70- to 80-year-olds, the rates were below 300 per 100,000 people, which should limit extreme pressure on the NHS if the lockdown starts to bring overall numbers down.
Patterns of excess deaths have changed
With the latest daily figures showing more than 1,000 deaths reported for the first time since April, the UK has moved again into a dangerous period. It also has one of the highest rates of “excess deaths” among advanced economies since the pandemic started, with more than 85,000 more deaths since mid-March than the average of the same period in the past five years.
The number of excess deaths last spring was twice that of the number of people who died after testing positive for the virus, when testing was strictly limited. With the daily death toll rising, the second wave has been different. In the autumn, excess deaths were lower than the daily Covid-19 death count, indicating that some of the people who died after catching the virus would have died anyway from other causes.
One reason for the suppressed levels of excess deaths in the second wave is that the virus was not allowed to spread unchecked through care homes, where tens of thousands of people died without being tested after almost certainly catching it in March and April.
Latest coronavirus news
Follow FT's live coverage and analysis of the global pandemic and the rapidly evolving economic crisis here.
Get alerts on Coronavirus pandemic when a new story is published