A variant of the Delta virus that is more infectious, but is less likely to cause symptoms, now accounts for more than one in 10 COVID cases in England, new research shows.
The latest results from the long-running REACT-1 study shows the prevalence of the AY.4.2 variant has been growing at a rate of 2.8% a day since September.
The variant is an evolutionary spin-off from the original Delta virus and is being closely tracked by the UK Health Security Agency.
Tests carried out between 19 October and 5 November on around 100,000 randomly selected people showed that 11.8% carried the variant.
But the data also shows that only 33% of those with the variant had the classic COVID symptoms of a fever, persistent cough, or a loss or change in taste or smell – compared to 46% of those with Delta.
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They were also less likely to show any other symptoms.
Professor Paul Elliott, director of the REACT programme at Imperial College London, said the variant appeared to be even more infectious than the more common Delta version of the virus.
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“Why it is more transmissible we don’t know. It does seem to be less symptomatic, which is a good thing,” he said.
Professor Christl Donnelly, another of the researchers, said it wasn’t clear how the variant would impact the pandemic.
“If it is less likely to be symptomatic, then it means it gets tested for less, and people may be out,” she said.
“On the other hand, if they are not coughing it might be spreading less far in distance.”
The UK Health Security Agency declared AY.4.2 a ‘variant under investigation’ on 20 October.
Research so far suggests it is associated with a slightly lower risk of hospitalisation and death than Delta. There does not appear to be a significant drop in vaccine effectiveness.
The latest REACT-1 results also show the booster dose is highly effective, reducing the risk of infection by two-thirds compared to people who have only had two doses.
A single dose of the vaccine given to school children reduces the risk of infection by 56% compared to those who have not had the jab.
Model Penny Lancaster has said she “felt ashamed and belittled” by how former MasterChef host Gregg Wallace treated her on the TV show.
Lancaster, who is also a TV personality, and is married to singer Rod Stewart, told Sky News’ The UK Tonight with Sarah-Jane Mee programme that she also felt let down by MasterChef’s production company Banijay UK.
“I didn’t feel like I was supported in that moment, I felt ashamed and belittled by the way Greg Wallace had treated me but equally I felt disappointed that the production company hadn’t come to my rescue,” Lancaster, 54 and a MasterChef contestant in 2021, said.
“There is a long way to go, but just by people coming forward and being honest about their experiences I think will help in the long term.”
At the end of July, Wallace, 60, apologised after a report commissioned by Banijay UK, and carried out by law firm Lewis Silkin, found 45 out of 83 allegations against him were substantiated.
Sir Rod Stewart criticised Wallace on Instagram in November 2024 and claimed he “humiliated” his wife when she was on the show.
He wrote: “Good riddance Wallace… You humiliated my wife when she was on the show, but you had that bit cut out didn’t you?
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“You’re a tubby, bald-headed, ill-mannered bully.”
He has previously apologised to people he has hurt, saying in July that he knows he has said things that have offended people. He has denied a specific allegation of unwanted touching.
The BBC referred Sky News to their statement from July, in which the corporation said: “Although the full extent of these issues were not known at the relevant time, opportunities were missed to address this behaviour – both by the production companies running MasterChef and the BBC. We accept more could and should have been done sooner.
“We want to thank all those who took part in the investigation, including those who first raised concerns directly with the BBC in November last year. We apologise to everyone who has been impacted by Mr Wallace’s behaviour.”
Image: Penny Lancaster speaks to Sarah-Jane Mee
Banijay UK, the producers of MasterChef, told Sky News: “We are extremely sorry to anyone who has been impacted by any inappropriate behaviour by Gregg Wallace whilst working on our shows and felt unable to speak up at the time or that their complaint was not adequately addressed.
“Ways of reporting concerns whilst working on our productions, protocols around behaviour and training for both cast and crew, have improved exponentially in recent years and we constantly review welfare procedures across our productions to ensure that they are as robust as they can be.”
Sadiq Khan has hit back at politicians “spreading misinformation” about safety in London as new data shows the number of violent crimes leading to injury has fallen in every borough over the past year.
Figures from the mayor’s office for policing and crime compare the 12 months ending in August 2025 with the previous 12 months – and show there were 8,749 fewer crimes which resulted in someone being hurt, a drop of nearly 12%.
The borough of Havering in east London recorded the largest drop (16.3%) followed by Enfield in north London (16.1%).
The smallest decreases were in Greenwich (4.3%) and Kensington and Chelsea (4.6%).
Sir Sadiq said: “We’ve seen a number of politicians here and across the globe talking down London and spreading misinformation about crime and safety in the capital.
“The evidence is clear, our approach to tackling crime and its complex causes works. It’s driving down violence right across the capital.”
His comments come after Donald Trump reignited his feud with Sir Sadiq earlier this month by accusing him of doing a “terrible job” and claiming “crime in London is through the roof”.
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The US president also hit out at the mayor in a speech at the UN General Assembly on Tuesday, where he also made the outlandish claim that London “wants Sharia law” – something there is no evidence for.
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Trump attacks UN and London mayor
Asked about the attacks, Sir Sadiq said: “I think President Trump has shown he is racist, he is sexist, he is misogynistic, and he is Islamophobic.”
He added that the public would be “wondering what it is about this Muslim mayor who leads a liberal, multicultural, progressive, successful city that means I appear to be living rent-free inside Donald Trump’s head”.
According to the mayor’s office, overall homicides in London are at a 10-year low, and the city’s rate is lower than in Berlin, Brussels, Madrid, Paris and all major US cities.
The rate of homicide was down by 17% in the 12-month period to June this year compared with the 12-month period to May 2016, it previously said.
Image: Sir Sadiq speaks with a police officer during a walkabout in the West End earlier this year. File pic: PA
Metropolitan Police Assistant Commissioner Rachel Williams said: “We’re targeting the most dangerous individuals, disrupting criminal networks, and investing in prevention to protect those most at risk.
“That’s why fewer people are being hurt, fewer lives are being lost, and London is becoming a safer city.”
The Conservatives rejected the suggestion that London is safer.
Image: Shadow home secretary Chris Philp claims ‘London isn’t safer’
Shadow home secretary Chris Philp said: “Under this Labour mayor, criminals know the odds are stacked in their favour.
“Only one in 20 robberies is solved, fewer offenders are being jailed, and more than a thousand police officers have been cut from the Metropolitan Police, with Sir Mark Rowley warning of further losses this year.
“Londoners don’t feel safer because London isn’t safer.”
A murder investigation is under way after a fatal stabbing in north London.
The Metropolitan Police said officers and the London Ambulance Service responded to reports of stabbing in Camden Gardens, NW1, after being called at 3.29pm on Saturday.
A 44-year-old man was treated at the scene for stab wounds before being taken to hospital, where he died.
Police are awaiting formal identification and a special post-mortem will take place, the force said.
Borough Commander Jason Sewart, who leads policing in Camden, said: “My team are working at pace to establish the full circumstances that led to this man’s tragic death in Camden Gardens.
“Our thoughts remain with the victim’s family and friends at this very difficult time. They continue to be supported by specialist officers.”
There will be increased patrols in the area as enquiries are made, he added. Anyone who many have information or CCTV footage is being asked to contact police.
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“This was an isolated incident and we do not believe there to be any threat to the wider public,” Cmdr Sewart said.