By ITV News Multimedia Producer Suzanne Elliott
For the past month, the UK has recorded more than 30,000 daily Covid-19 cases - with the figure regularly topping 40,000.
Figures from the Office for National Statistics (ONS) on Friday showed coronavirus infection levels in England are getting close to the peak seen at the height of the second wave
On Monday, the UK reported 48,965 new confirmed cases - more than any other country except the US, and more than the EU combined.
Of the 233,644 cases reported worldwide on October 17, 43,738 were in the UK - that’s more than one in six Covid cases in the world - although many countries have a limited testing capacity and so may not have accurately recorded their results.
While the vaccination programme has meant the high case load has not translated into the hospitalisations and deaths we saw in the first and second waves, there is still a link: Tuesday saw the highest daily death toll in England since March. What is driving these high infection rates and where will it lead?
What is behind these high cases number?
Professor Paul Hunter, Professor in Medicine at The Norwich School of Medicine, University of East Anglia, says the picture is "complicated" and there is no one reason for these rising cases.
"It's complicated because there's all sorts of things going on. And although we probably, or at least I certainly understand each individual piece of the jigsaw, I don't think any one of us totally understands how they all fit together," he told ITV News.
But there are some drivers that, "have some role to play" in influencing these numbers.
The ONS suggests the infection rates are mostly being driven by rates among schoolchildren.
Around one in 10 schoolchildren in years seven to 11 in England was estimated to have Covid in the second week of October, the highest positivity rate for any age group.
Teenage vaccination rates in the UK are lagging behind most European countries who are also giving this age group two doses, not just a single one as is the case in this country currently.
But while around half of Covid infections are in the young, the balance is starting to shift slightly, and we are beginning to see an increase in older people which is likely driving an uptick in hospitalisations.
The UK is testing far more than many other countries, including regularly testing school children, which may explain the country's comparatively high case load.
"We're doing a hell of a lot more testing per head of population than most of our neighbours, and particularly we're testing a large number of otherwise asymptomatic or only mildly ill children," Prof Hunter says.
"And so, we will be picking up a lot more infections and reporting on a lot more infections than other on the neighbours."
Experts believe this could also be a factor, with some evidence protection against infection is beginning to wear off. The booster vaccination programme has been sluggish, with nowhere near the same take-up as the original jab rollout. Around three million of an eligible eight million people have so far come forward for a third shot.
Prof Hunter says: "Vaccines are waning in their ability to protect people against infection. And that's obvious, and that was expected. Immunity to Covid viruses doesn't last very long.
"That's immunity to infection, immunity against severe disease is more robust, and seems to be holding up, by and large, although ultimately that will decline with time as well."
No social distancing restrictions
The lifting of all restrictions on July 19 in England was always going to lead to a spike in infections as life returned, in the most part, to normal. Lack of social distancing and increased mixing - including inside bars, theatres and nightclubs - was always going to trigger a spike in infections.
The Delta variant
The Delta variant, which emerged around this time last year, is now by far the dominant strain in the UK, accounting for 99% of infections. Vaccines are slightly less effective against Delta than they are against Alpha, although they are just as effective against severe disease from the original virus.
A new variant?
The government is keeping a “close eye” on a descendant of the coronavirus Delta variant that is being seen in a growing number of cases.
Scientists say AY4.2 carries two characteristic mutations in the spike, Y145H and A222V, both of which have been found in various other coronavirus lineages since the beginning of the pandemic.
However, they have remained at low frequency until now.
Could this variant be behind the surge in infections?
Prof Hunter says: "It's too early to be really sure what's going on with it. But early indications are that is a little bit more infectious, maybe about 10%.
"So, not enough, probably at the moment to be explaining what's happened in recent weeks but may actually become a bit more important as we go forward."
Why is the UK seeing much higher Covid rates than other countries?
Testing is a factor here. The UK's high testing rate is bound to affect numbers, as Prof Hunter said above, but there is also no hiding from the fact it is not the only reason.
Could the UK's relaxed Covid rules be driving these sky high figures?
Western European countries have kept in place more control measures, vaccine mandates, mask-wearing mandates, and tend to have lower case numbers and certainly not case numbers which are going up as fast as the UK has got.
“Other countries aren't testing as much as us, but there are lots of factors,” Dr Sarah Jarvis told ITV News.
“I have several colleagues who are doctors in other countries, one who is in Portugal I was speaking to just last week, everybody was wearing face coverings, nobody would dream of doing anything without the face covering.
“Many countries in Europe have vaccine passports to get into cinemas, theatres, to any venue, even into restaurants. We have very little of that. And I think that a lot of people believe it's all over. I was on the tube recently, and I was horrified at how few people are wearing face coverings.”
But Prof Hunter points out that while restrictions in UK - and England in particular - are more relaxed than many other nations, we are actually mixing less than many other countries.
"We do technically have one of the more relaxed legislations than Europe but when you look at things like Google mobility data, we're not actually that different in our mixing, going to work, then many European countries and indeed, we're mixing less than some according to Google mobility data, like France, for example."
Prof Hunter also says that the UK relied more on AstraZeneca compared to our European neighbours, which is less effective at preventing infection - but just as effective against preventing severe disease - as Pfizer or Moderna.
Should we be worried?
The vaccination programme offers us a great deal more protection than during the first two waves, but high infection rates will inevitably trickle down to more hospitalisations and deaths, as well as putting more people at risk of long term health problems associated with Covid.
Prof Kevin McConway, Emeritus Professor of Applied Statistics, The Open University, said: “Of course, the effect of having an infection rate as high as this in England – or indeed in Scotland or Wales where the infection rate for the whole population isn’t much different – isn’t anywhere near as serious as it was when the rate was last this high, because of vaccinations reducing the risk of severe illness or death, if someone becomes infected. However, that doesn’t mean that we shouldn’t be concerned about it.”
Prof Jim Naismith, Director of the Rosalind Franklin Institute, and Professor of Structural Biology, University of Oxford, said: “Sadly, at the moment the UK has a higher level of Covid-19 than most other comparable countries, this is seen not just in positive tests but in hospital admissions and deaths.
“We should remember that around 1,000 people die of Covid every week in the UK, each of those deaths represents a tragedy.
“High case numbers will mean more long Covid-19.
“The strong start in vaccination has faded and the UK now lags several comparable countries in the EU. The UK is still ahead in vaccine coverage than many other countries, including the USA."
But it is far from doom and gloom. The vaccination programme has propelled us a long way from where we were last year and the booster rollout, despite its sluggish start, could begin to have a small impact in the coming weeks.
"Although the booster vaccination campaign isn't doing as well as the second campaign, it's still going, and there are some early indications that that might be having effect in the over 80s, in slowing the epidemic in the age group," Prof Hunter says
He also draws attention to the oscillating figures that make it difficult to predict where we will be next week, let alone next month, and that there are some early indications that the case numbers we have been seeing, might be levelling off, although he adds "it's just too early to be absolutely certain one way or the other".
Will this mean a return to restrictions?
The government has ruled out bringing in England's “Plan B” Covid restrictions.
As well as a return of mandatory face masks, Plan B could also involve introducing vaccine passports for nightclub entry - and work from home advice could return.
Dr Julian Tang, Honorary Associate Professor/Clinical Virologist, Respiratory Sciences, University of Leicester, said: “It has been surprising that the recent gradually increasing daily Covid-19 cases and deaths have just been mostly accepted by many of us, as just ‘living with the virus’ and an unavoidable consequence of opening up the economy and schools.
“But as the number of Covid-19 deaths increases, in combination with those from flu, this may change, and some return of social distancing and masking may be required - and perhaps be more acceptable - going into winter when flu traditionally peaks.”