The number of Delta variant cases across the UK has trebled in a week, according to analysis by Public Health England published on Friday. There are now 42,323 cases of the variant, which first originated in India, up from 12,431 in the week to 3 June.
The variant, which is thought to be 60 per cent more transmissible than the Alpha variant, accounts for more than 90 per cent of new Covid-19 cases in the UK. The rate of growth in infections across regions is currently showing a doubling time of between 4.5 days to 11.5 days.
The rapid spread of the strain has ramped up concerns that the prime minister pressing ahead with his roadmap to bring an end to precautionary measures could have disastrous consequences.
The surging number of cases have led the vice-president of the Association of Directors of Public Health, Jim McManus, to call for the final step to be postponed, saying that unlocking on 21 June risks “derailing our path back to normality”.
“Patience now will pay off in the long run,” he said, arguing for a delay to “allow time for more people to be vaccinated and protected against the Delta variant”.
The latest data comes as ministers reportedly consider a delay of up to four weeks, withThe Timesreporting that a longer postponement is being reviewed as a way of ensuring businesses can have “certainty” in their reopening plans. The merits of a shorter, two-week extension are also being considered.
A number of scientists have called for the 21 June date to be pushed back, stating that the UK is at the beginning of a third wave.
Appearing on BBC Radio 4’s Today programme in late May, microbiologist and member of the New and Emerging Respiratory Virus Threats Advisory Group (Nervtag) Professor Ravi Gupta said there already appeared to be signs of a new wave.
“There has been exponential growth in the number of the new cases and at least three-quarters of them are the new variant.
“Of course the numbers of cases are relatively low at the moment – all waves start with low numbers of cases that grumble in the background and then become explosive, so the key here is that what we are seeing here is the signs of an early wave.”
He added: “It will probably take longer than earlier waves to emerge because of the fact that we do have quite high levels of vaccination in the population, so there may be a false sense of security for some time, and that’s our concern.”
Professor Gupta pointed out that Mr Johnson’s roadmap was formulated before the existence of the more transmissible variant became unknown and advocated delaying the final easing by “a few weeks” to allow more people to be vaccinated against it.
“If you look at the costs and benefits of getting it wrong, I think it is heavily in favour of delay, so I think that's the key thing,” the University of Cambridge expert said.
“People are not saying we should abandon the 21 June date altogether but just to delay it by a few weeks while we gather more intelligence and we can look at the trajectory in a clearer way.”
On Times Radio, Professor Adam Finn of the Joint Committee on Vaccination and Immunisation went further and questioned whether the restrictions already lifted might need to be reimposed.
“We’d all be better off doing everything we can to minimise that risk so that we don’t get to a position where we have to really go backwards in terms of the restrictions that we’re all having to endure,” he said in late May.
The experts are broadly in agreement about the threat posed by the Delta variant and the risk of a major setback being caused by ending restrictions prematurely.
Martin McKee, a professor of European public health at the London School of Hygiene and Tropical Medicine, told The Guardian that he also believes a third wave has already begun.
“We can already see that the current measures are not stopping cases rising rapidly in many parts of the country. This looks very much as if we are now early in a third wave,” he said.
“Unless there is a miracle, opening up further in June is a huge risk. The rise in cases we are seeing now should cause a reassessment of the most recent relaxation.”
James Naismith, a professor of structural biology at the University of Oxford, likewise told the AP news agency: “It seems almost certain that we will face a third episode of rising Covid-19 infections.
“It seems likely that the Indian variant will mostly confine itself to the unvaccinated younger population. It is much less likely to cause serious disease in this group. However, less likely is not the same as zero. With large enough numbers of infections, appreciable numbers will get seriously ill.”
It is feared that the NHS could once again be left struggling to cope in the event of a fresh explosion of cases as the health service begins the difficult job of addressing its non-Covid workload, which has piled up over the course of the pandemic as operations and treatments were sidelined in order to prioritise bringing the outbreak under control.
Downing Street has so far said it is too soon to make a call on delaying the 21 June unlocking and that more data is needed to determine the severity of the situation, a position echoed by chancellor Rishi Sunak, who told The Mail on Sunday: “We will know more as we approach the date.”
Speaking on BBC One’s Andrew Marr Show on Sunday, vaccines minister Nadhim Zahawi said a decision would be made on 14 June and commented: “We have to look at the data and we will share that with the country. It would be completely wrong for me to now speculate.
“At the moment, we don’t have enough data. There are some parts of the country where there’s literally no B.1.617.2 and everything is pretty stable; in other parts of the country it is beginning to overtake the B.1.1.7 variant – the Kent variant.”
When did the first and second waves begin?
Here’s a reminder of how the previous two tsunamis of infections came crashing down on these shores last year.
Following the virus’s outbreak in the city of Wuhan in China towards the end of 2019, it gradually spread from Asia to the Mediterrean, with Italy the first European nation to be badly hit.
In the first half of March 2020, the threat posed by coronavirus was becoming clear but the UK government was unsure how best to go about tackling it - as the PM’s adviser Dominic Cummings made clear in his parliamentary testimony last week.
On 23 March, Mr Johnson reluctantly announced the first full national lockdown, telling the public they will only be allowed to leave their homes for limited reasons, including food shopping, exercise once per day, medical need and travelling for work when absolutely necessary. All shops selling non-essential goods were told to close, while gatherings of more than two people in public were banned.
After Mr Johnson himself had been hospitalised with Covid-19, he announced the first easing on 10 May, followed by more as the summer progressed.
But, by 30 July, health secretary Matt Hancock was warning of a “second wave starting to roll across Europe”. Six weeks later, on 18 September, Mr Johnson said the next round had reached Britain and introduced new restrictions later that week to contain its spread, stopping short of a second national lockdown. A total of 6,634 new coronavirus cases were recorded on 24 September, at that point the highest single-day figure since the outbreak began.
The tier system was then introduced on 12 October before being replaced by a new month-long second national lockdown between November and December, before a respite for the Christmas holidays.
A third national lockdown followed on 4 January as cases soared, before the situation gradually eased again and enabled the PM to announce his roadmap out of restrictions on 22 February, which we are currently on course to reach the end of on 21 June, unless the government does change tack in response to the Delta variant.