Ruth Hutt said there was a risk the mutant strain was spreading in the community
Everyone in Lambeth and Wandsworth was today urged to book a coronavirus test after a cluster of the troublesome South African variant was spotted in the two London boroughs.
Public Health England revealed last night up to 74 cases of the mutant strain were discovered in the council areas, in what officials called a ‘significant’ outbreak.
Health chiefs have now asked anyone over the age of 11 who lives in, works in, or travels through either borough to get tested. The variant, known as B.1.351, is of concern because it is feared it may be able to partially evade existing vaccines.
Dr Ruth Hutt, director of public health for Lambeth Council, insisted officials were ‘fairly confident’ most cases had been found.
But she added there was a risk cases of the variant had already spilled over into the wider community. A cluster of infections was picked up in a care home.
Dr Hutt told BBC Radio 4’s Today programme that residents of the two boroughs can still enjoy the easing of lockdown — but urged them to do so ‘safely’.
‘It is a really good opportunity now to mobilise all this testing just to check we don’t have any further cases of this variant in either Lambeth or Wandsworth,’ she said.
Dr Hutt added that ‘a lot’ of the cases were picked up through asymptomatic testing, saying it was proof that there were ‘really good testing processes in place’.
She said: ‘What we want to do is a wider testing across the public of anybody who doesn’t have symptoms to check there aren’t further cases out there that we may have missed.’
Ministers have been fighting to stop the mutant variant from spreading rapidly. More than 540 cases have already been spotted in Britain.
Surge testing has been used in dozens of areas where the variant has been detected. Travellers are also asked to quarantine, in an attempt to stop cases being imported.
More than 70 people in Wandsworth and Lambeth are being forced to self-isolate after reportedly contracting the South African variant that could weaken the vaccine
People stand socially distanced as they queue to enter to take a Covid test at a mobile novel coronavirus testing centre in Brockwell Park in south London
Testing volunteers are pictured at the make-shift swabbing site in Brockwell Park this morning
The Department of Health has said 44 confirmed Covid-19 cases have been found predominantly in Wandsworth and Lambeth (pictured, Lambeth town hall)
WHY ARE SCIENTISTS SO SCARED OF THE SOUTH AFRICAN VARIANT?
The variant has mutations on its spike protein which scientists fear will make it difficult for the immune system to recognise, even in vaccinated people
Real name: B.1.351
When and where was it discovered?
Scientists first noticed in December 2020 that the variant, named B.1.351, was genetically different in a way that could change how it acts.
It was picked up through random genetic sampling of swabs submitted by people testing positive for the virus, and was first found in Nelson Mandela Bay, around Port Elizabeth.
Using a computer to analyse the genetic code of the virus – which is viewed as a sequence of letters that correspond to thousands of molecules called nucleotides – can help experts to see where the code has changed and how this affects the virus.
What mutations did scientists find?
There are two key mutations on the South African variant that appear to give it an advantage over older versions of the virus – these are called N501Y and E484K.
Both are on the spike protein of the virus, which is a part of its outer shell that it uses to stick to cells inside the body, and which the immune system uses as a target.
They appear to make the virus spread faster and may give it the ability to slip past immune cells that have been made in response to a previous infection or a vaccine.
What does N501Y do?
N501Y changes the spike in a way which makes it better at binding to cells inside the body.
This means the viruses have a higher success rate when trying to enter cells when they get inside the body, meaning that it is more infectious and faster to spread.
This corresponds to a rise in the R rate of the virus, meaning each infected person passes it on to more others.
N501Y is also found in the Kent variant found in England, and the two Brazilian variants of concern – P.1. and P.2.
What does E484K do?
The E484K mutation found on the South African variant is more concerning because it tampers with the way immune cells latch onto the virus and destroy it.
Antibodies – substances made by the immune system – appear to be less able to recognise and attack viruses with the E484K mutation if they were made in response to a version of the virus that didn’t have the mutation.
Antibodies are extremely specific and can be outwitted by a virus that changes radically, even if it is essentially the same virus.
South African academics found that 48 per cent of blood samples from people who had been infected in the past did not show an immune response to the new variant. One researcher said it was ‘clear that we have a problem’.
Vaccine makers, however, have tried to reassure the public that their vaccines will still work well and will only be made slightly less effective by the variant.
How many people in the UK have been infected with the variant?
At least 544 Brits have been infected with this variant, according to Public Health England’s random sampling.
The number may be higher, however, because PHE has only picked up these cases by randomly scanning genetic sequences of cases identified.
They are thought to have covered every case last week.
Will vaccines still work against the variant?
So far, Pfizer and Moderna’s jabs appear only slightly less effective against the South African variant.
Researchers took blood samples from vaccinated patients and exposed them to an engineered virus with the worrying E484K mutation found on the South African variant.
They found there was a noticeable reduction in the production of antibodies, which are virus-fighting proteins made in the blood after vaccination or natural infection.
But it still made enough to hit the threshold required to kill the virus and to prevent serious illness, they believe.
There are still concerns about how effective a single dose of vaccine will be against the strain. So far Pfizer and Moderna’s studies have only looked at how people given two doses react to the South African variant.
Studies into how well Oxford University/AstraZeneca‘s jab will work against the South African strain are still ongoing.
Johnson & Johnson actually trialled its jab in South Africa while the variant was circulating and confirmed that it blocked 57 per cent of coronavirus infections in South Africa, which meets the World Health Organization’s 50 per cent efficacy threshold.
Surge PCR testing is available for people aged 11 and over who live, work or travel through these boroughs.
PHE revealed yesterday there were 44 confirmed cases of the variant in the areas, and 30 probably cases linked to these individuals.
The chief medical adviser for NHS Test and Trace, Dr Susan Hopkins, said the clusters were ‘significant’.
‘It’s really important people in the local area play their part in stopping any further spread within the local community,’ she added.
‘Around one in three people with Covid don’t show any symptoms.
‘By taking part you can protect yourselves and your loved ones and help us identify any possible new cases that would otherwise be missed, preventing further transmission and saving lives.’
The B.1.351 strain has three key mutations on its spike protein which help it ‘hide’ from the immune system, known as E484K, N501Y and K417N.
Covid uses its spike to latch onto human cells and the current crop of vaccines have been designed to train people’s bodies to recognise that protein.
But any deformities make it harder for the immune system to spot and flush it out, allowing the virus to take hold.
No10’s scientific advisers fear the South African variant — which has yet to take hold in the UK — may make the current crop of vaccines around 30 per cent less effective.
Analysis by SAGE found the strain can cause up to a 10-fold decrease in the effectiveness of antibodies in vaccinated or previously infected people.
While antibodies are not the only part of the immune response against Covid — white blood cells also help — they play a crucial role in fighting off the infection.
Nonetheless, experts are still confident the jab is strong enough to protect the vast majority of people from falling severely ill with the B.1.351 strain.
South Africa — which has been ravaged by the variant — has already suspended the use of AstraZeneca’s vaccine, citing concerns it is not effective enough.
And real-world data from Israel last week suggested the strain may also evade the protection provided by Pfizer’s vaccine to some extent.
But separate studies have sought to downplay fears, with one suggesting the Pfizer jab offers 100 per cent protection against the Brazilian and South African variants.
Researchers in Israel compared almost 400 people who had tested positive for Covid, 14 days or more after they received one or two doses of the vaccine, against the same number of unvaccinated patients with the disease.
The variant was found to make up about one per cent of all the Covid cases across all the people studied, according to the study by Tel Aviv University and Israel’s largest health provider Clalit.
But among patients who had received two doses of the vaccine, its prevalence rate was eight times higher than those unvaccinated – 5.4 per cent versus 0.7 per cent.
This suggested the jab is less effective against the South African variant, compared with the original Covid and a variant first identified in Britain that has come to comprise nearly all Covid cases in Israel, the researchers said.
‘This means that the South African variant is able, to some extent, to break through the vaccine’s protection,’ said Tel Aviv University Professor Adi Stern.
The research cautioned, however, that the study only had a small sample size of people infected with the variant because of its rarity in Israel.
They also said the research was not intended to deduce overall jab effectiveness against any variant, since it only looked at people who had already tested positive for Covid.
Some previous studies have indicated that the Pfizer shot was less potent against B.1.351 variant than against other variants of Covid, but still offered robust defence.
It comes as England’s Covid vaccination roll-out was expanded to over-45s today.
But the NHS website for booking appointments crashed just moments after the drive was officially opened up to younger adults.
Users trying to get a jab were told: ‘The NHS site is currently experiencing technical difficulties. We are working to resolve these issues. Thank you for your patience.’
Other users reported being placed in a queue with a holding screen which read: ‘You are in a queue. Lots of people [are] trying to book an appointment.’
Health chiefs have moved on to the next stage of the campaign because No10 hit its April 15 goal of offering everyone in the top nine priority groups their first dose three days ahead of schedule.
But shortly after the site crashed, Vaccines Minister Nadhim Zahawi tweeted that the problem had been ‘fixed’.
Moderna’s vaccine is also being dished out in England from today. But only 20 sites will get supplies of the US company’s jab this week, as supply trickles in at around 150,000 a week.
Ministers have bought 17million doses of Moderna’s vaccine, which is the third to be added to the NHS’ ‘armoury’, alongside jabs from Oxford/AstraZeneca and Pfizer.
Moderna’s jab — as well as leftover supplies of AstraZeneca and Pfizer that haven’t been reserved for second doses — will be used to move on to the next phase of the roll-out.
Boris Johnson hailed the ‘hugely significant milestone’ in the race to inoculate the country, as he said the Government would ‘move forward’ on its next goal of inviting every adult for a vaccine by the end of July.
Despite moving on to the next phase of the roll-out, parts of England have still only vaccinated half of citizens over the age of 50.
Some areas of the country have stormed ahead and managed to reach more than 96 per cent of people in their 50s, 60s, 70s, 80s and above, exceeding Number 10’s ambitions.
But others have been sluggish for months, with large sections of their middle-aged and elderly populations still unprotected against Covid.
Official data analysed by MailOnline shows that 36 areas of the country have given a Covid jab to fewer than 60 per cent of people in the high-risk age groups.
London has had the least successful rollout so far and is home to six of the 10 lowest uptake areas.
Official data show that 36 areas have given a Covid jab to less than 60 per cent of people in the high-risk age groups. London has a large proportion of the worst-performing areas