Britain still far off herd immunity as just 1-in-16 people are infected

Just one in 16 people in England were infected with Covid-19 during the first wave of the pandemic, a major study has found. 

The figure accounts for around six per cent of the nation, the equivalent of 3.4million people. 

But the same data from Imperial College London researchers suggested 17 per cent of black people and 12 per cent of Asian people have already had the virus.

Experts carried out a mass Covid-19 surveillance study involving 100,000 volunteers who used home-testing kits to check for antibodies, which reveal if someone has previously been infected. 

The results, which come amid a spike in cases across England, suggest the country is far from reaching herd immunity – when enough of the population has been exposed to a disease that it can no longer spread. 

And the data adds to evidence that shows BAME people face a higher risk of getting infected and becoming severely ill or dying. 

Scientists have yet to pinpoint exactly why they face a greater risk – but experts have speculated it could be down to ethnic minorities being more likely to be poor and therefore in worse health, and more likely to work in public-facing jobs where they are more prone to catching the illness. 

Around six per cent of the population, one in 16, in England were infected with Covid-19 by July 13, a study by Imperial College London has found. (Stock image)

Around six per cent of the population, one in 16, in England were infected with Covid-19 by July 13, a study by Imperial College London has found. (Stock image)

Around six per cent of the population, one in 16, in England were infected with Covid-19 by July 13, a study by Imperial College London has found. (Stock image)

WHY ARE BAME PEOPLE MORE AT RISK OF CORONAVIRUS? 

Experts say there is unlikely to be one sole reason as to why ethnic minorities are more likely to become severely ill or die from the virus.

People from ethnic minority backgrounds make up a large amount of the NHS workforce.

This exposes them to bigger loads of the virus more often because they come into face-to-face contact with gravely ill patients.

Having a high viral load – the number of particles of the virus someone is first infected with – gives the bug a ‘jump start’, scientists say.

Members of ethnic minority communities are twice as likely to be affected by poverty, and are often hit the hardest by chronic diseases.

Those living in poverty smoke and drink alcohol more and are more likely to be obese – all of which increase the likelihood of chronic health conditions.

Patients with pre-existing health troubles struggle to fight off COVID-19 before it causes deadly complications such as pneumonia.

People from poorer backgrounds are also more likely to use public transport more often and live in crowded houses – driving up their chance of catching and spreading the virus. 

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The programme suggested a total of 13 per cent of people living in London had Covid-19 antibodies, compared with less than three per cent in the South West of England.  

Meanwhile people working in care homes (16 per cent) and health care (12 per cent) returned far higher results than people who were not key workers, at five per cent. 

The study found 17 per cent of black volunteers had antibodies while the categories of Asian and ‘other’ ethnic minorities had 12 per cent each. The figure among white volunteers was five per cent. 

People aged from 18-34 showed the highest incidence of antibodies, at eight per cent, while over-65s had the lowest rate at just three per cent 

The major study also found that coronavirus killed around 1.23 per cent of all infected patients and 3.4million people in England may have been infected with Covid-19.

Professor Graham Cooke, who led the research, told The Times: ‘Clearly the numbers are still very big and that explains the high levels of mortality we’ve seen, but as a proportion of the overall population it’s still relatively small, except in some groups where the prevalence is higher, such as for people of Asian and black ethnicity.’

He added: ‘It means that if we had relaxation of the lockdown completely, we wouldn’t have a very protected population so we would expect the virus to return. I think that has implications for decisions that are made.’ 

Department of Health data shows only 313,798 cases have been diagnosed since the outbreak began. 

But hundreds of thousands of infected Brits were not tested during the height of the crisis, either because of a lack of swabs or because they never had any of the tell-tale symptoms.

Counting how many people who have coronavirus antibodies is, therefore, the most accurate way of calculating how much of the population has already been infected.  

But research has suggested that antibodies decline three months after infection — meaning only a fraction of true cases during the peak of the crisis in March and April may have been spotted. 

Experts have been baffled over the true infection fatality rate of the disease since the start of the pandemic in December. Antibody surveillance studies have produced wildly different results across the world, ranging from as low as 0.25 per cent to 1.4 per cent. One study even suggested it was as high as 7.4 per cent

Experts have been baffled over the true infection fatality rate of the disease since the start of the pandemic in December. Antibody surveillance studies have produced wildly different results across the world, ranging from as low as 0.25 per cent to 1.4 per cent. One study even suggested it was as high as 7.4 per cent

Experts have been baffled over the true infection fatality rate of the disease since the start of the pandemic in December. Antibody surveillance studies have produced wildly different results across the world, ranging from as low as 0.25 per cent to 1.4 per cent. One study even suggested it was as high as 7.4 per cent

HOW DEADLY IS COVID-19?

Experts have been baffled over the true infection fatality rate (IFR) of the disease since the start of the pandemic in December.

World Health Organization chiefs first claimed the infection-fatality rate was 3.4 per cent but last week changed its estimate to 0.6 per cent.

Antibody surveillance studies have produced wildly different results across the world, ranging from as low as 0.25 per cent to 1.4 per cent. 

The lowest the IFR could possibly be in the UK is 0.06 per cent, if all 66million people living in Britain had already had the coronavirus.

That estimate is based on the UK’s 46,000 confirmed victims, who have tested positive for Covid-19 and died potentially months after recovering. The figure is still 0.06 per cent for the revised death toll of 41,000.

If the WHO’s estimate of 0.6 per cent is true, then it would mean around 6.8m people in Britain have already had the disease.

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And some people may never develop antibodies at all, so the true number of cases will always be a mystery.

The Imperial study is in line with estimates from other antibody surveillance studies, including one led by a team at Cambridge University.

Cambridge academics — who have been making forecasts based on an array of data — last week calculated around eight per cent of England has had the disease.

The Imperial study also found volunteers in the most deprived areas of the country were slightly more likely to have antibodies than those in the wealthiest areas, at seven per cent compared with five per cent, while those in households of more than six or seven people (12 per cent and 13 per cent) were more likely to have had Covid-19 than those in single or two-person households (five per cent). 

Smokers were slightly less likely to have antibodies than non-smokers – at three per cent compared with five per cent – while 32 per cent of people with antibodies had shown no symptoms, a figure which rose to 49 per cent of those aged older than 65.

One of the scientists behind the study said that the coronavirus outbreak in the UK appeared to have been ‘widely dispersed’ from the start.

The first patient to die with Covid-19 in the UK was recorded on March 5, when it was thought there were only 90 cases in the UK.

Professor Helen Ward told BBC Breakfast: ‘What was interesting (about the study) is that we can tell from people who reported not only having a positive test, but we also asked about their symptoms so we can actually track for most people – the 70 per cent of people who reported symptoms – when they think they were infected.

‘And it did start in January, February, and actually it started right across the country, so you can’t say that it started in London and spread out.

‘Right from the beginning it was widely dispersed.’

Health Minister Edward Argar hailed the study as an important development in Britain’s fight against the coronavirus.

‘Large scale antibody surveillance studies are crucial to helping us understand how the virus has spread across the country and whether there are specific groups who are more vulnerable, as we continue our work to drive down the spread of the disease,’ Mr Argar said in a statement.

Pictured above are graphs displaying the UK’s death and infection totals before the Covid-19 death toll was revised yesterday. The number of infections thus far is in fact around 315,000

‘We don’t yet know that antibodies provide immunity to coronavirus, but the more information we can gather on this virus, and the easier we can make it for people to participate in these studies, the better equipped we will be to respond.

‘The British public have already played a massive part in helping to keep the country safe and I’d urge them to consider signing up to one of the many vital surveillance studies taking place over the coming months as part of our national testing effort.’

The study’s authors also cautioned there was still no firm evidence the presence of antibodies meant people could no be re-infected with the virus.

Professor Graham Cooke, the research professor of infectious diseases and research lead at Imperial, said: ‘Using the finger-prick tests suitable for large scale home testing has given us clearest insight yet into the spread of the virus in the country and who has been at greatest risk.

‘These data will have important implications as decisions to ease lockdown restrictions in England.’

WHAT ARE ANTIBODIES? AND DOES HAVING THEM MEAN YOU’RE IMMUNE? 

Antibodies are substances produced by the immune system which store memories of how to fight off a specific virus.

They can only be created if the body is exposed to the virus by getting infected for real, or through a vaccine or other type of specialist immune therapy.

Generally speaking, antibodies produce immunity to a virus because they are redeployed if it enters the body for a second time, defeating the bug faster than it can take hold and cause an illness.

An antibody test, which involves analysis of someone’s blood sample, has two purposes: to reveal whether an individual has been infected in the past and may therefore be protected against the virus, and to count those people.

Knowing you are immune to a virus – although whether people actually develop immunity to Covid-19 is still unknown – can affect how you act in the future.

Someone may need to protect themselves less if they know they have been infected, for example, or medical staff may be able to return to work in the knowledge they are not at risk.

Counting the numbers of people who have antibodies is the most accurate way of calculating how many people in a population have had the virus already.

This can be done on a small sample of the population and the figures scaled up to give a picture of the country as a whole.

In turn, this can inform scientists and politicians how devastating a second outbreak might be, and how close the country is to herd immunity – a situation in which so many people have had the virus already that it would not be able to spread quickly a second time.

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