UK's contact tracing scheme will only cut infections by 5% because not everyone will comply and test results are still too slow, leading scientists warn

  • Royal Society scientists modelled what effect the scheme would have on crisis
  • Found infections would only drop by between 5 and 15%, in best case scenario 
  • Testing can still take five days, by which time patients likely to have spread virus 

The Government’s contact tracing programme will only bring down infections by a mere 5 per cent, according to Royal Society scientists.

World-leading experts from the prestigious scientific academy warned the scheme was 'not a silver bullet' and will only have a 'modest' effect on the UK's crisis.

The scientists said that testing times were still too slow and there was a good chance many Britons do not adhere to self-isolation rules. 

They modelled what effect contact tracing would have on Britain' epidemic and found that, even if compliance is 80 per cent and the Government speeds up its testing, the number of new cases will only drop by up to 15 per cent.

The report, by the Data Evaluation and Learning for Viral Epidemics (DELVE) group, has been handed to SAGE scientists ahead of the rollout of the contact tracing programme tomorrow. 

The ef of different intervention strategies to preventing Covid-19 infections. S1 to S5 are increasingly stringent measures. S1 involves no restrictions on social interaction, only requiring households of symptomatic individuals to quarantine. S5 reflects the current situation

The contributions of different intervention strategies in preventing Covid-19 infections: S1 to S5 are increasingly stringent measures, with S1 involving no restrictions on social interaction, only requiring households of symptomatic individuals to quarantine. S5 reflects the current situation

The impact of varying delays in testing cases and tracing close contacts (left) on the reproduction 'R' value . The impact of varying compliance with steps in the TTI system (right)

The impact of varying delays in testing cases and tracing close contacts (left) on the reproduction 'R' value . The impact of varying compliance with steps in the TTI system (right)

The Government will launch a widespread contact tracing scheme to track down people who have been in touch with infected patients starting tomorrow

The Government will launch a widespread contact tracing scheme to track down people who have been in touch with infected patients starting tomorrow

It will be supported by the new NHSX app, which uses Bluetooth technology to alert people when they’ve been close to a COVID-19 patient

It will be supported by the new NHSX app, which uses Bluetooth technology to alert people when they’ve been close to a COVID-19 patient

In it, Royal Society academics urge ministers to focus their efforts on bringing down the average time it takes to produce a COVID-19 test result.

Currently, swabs can take up to five days to be carried out, posted to a laboratory and analysed.

If this can be slashed to three days, then the Test, Trace and Isolate (TTI) programme could see infections fall by as much as 15 per cent, DELVE says.

Nobel Prize laureate Venki Ramakrishnan, chair of the DELVE committee, said the UK's scheme should by no means 'be considered as a silver bullet’.

The professor of structural biology said TTI has the potential to ‘play an important part in bringing this pandemic under control’ but social distancing and stringent hand-washing protocol would be just as important.

HOW WILL CONTACT TRACERS WORK ALONGSIDE THE NHS APP? 

The bulk of contact tracing work will be contracted out to at least two companies, including Serco, who are being asked to provide 15,000 call centre staff. 

They will designated specific areas of the country and will receive alerts when NHSX app users come into contact with suspected patients.

It is their job to phone these people and advise they self isolate and be vigilant about changes in their health and about social distancing. If they become ill, they will be tested.

If a contact becomes infected, the same process begins for them and their social network. The idea is to keep track of how the virus moves through social circles and to try to stay a step ahead of it and prevent wider spread. 

Ministers have also promised an additional 3,000 former doctors and nurses who have been recruited from the pool of retired NHS staff who volunteered to return to help during the pandemic.   

They will be able to provide medical advice to confirmed and suspected patients.  

The tracers will make a list of people considered to have been put at risk by the patient, and those people will be notified that they might have the coronavirus.    

The NHSX app would need more than 70 per cent of the UK population to download and use it for it to be effective.

But ministers say physical contact tracing will make up for the shortcomings of the app if update is below 70 per cent.

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Starting tomorrow, everyone who displays coronavirus symptoms will be asked to report themselves to ‘test and trace’ officials either online or through a new helpline.

Their job will be to find, test and isolate these people and contact anyone who they have had close interactions with.

Family members, flatmates, partners and close contacts will be told to go into isolation for a fortnight even if they have no symptoms.

Anyone told to self quarantine will be entitled to statutory sick pay, or if they are self-employed they will have access to Government grants.

The TTI programme is seen as critical for pulling the country out of lockdown. But DELVE has warned that it will only work if the overwhelming majority of Britons comply.

Professor Anne Johnson, an epidemiologist at University College London and a member of the DELVE committee, said: ‘One of the keys to success of any potential TTI programme will be ensuring that it is carried out in an integrated way – joining up Public Health England, NHSX, primary and community care and the various other strands required to deliver a truly national effort.

‘Fast testing also allows those who are not infected, and their families, to carry on with their lives. There are many potential pitfalls for such a system and it is important that all of those are carefully considered in introducing such a complex undertaking.’

The TTI programme will be supported by the new NHSX app, which uses Bluetooth technology to alert people when they’ve been close to a COVID-19 patient.

After some technical problems and concerns about data privacy, officials say the app is now on course for a national rollout within weeks, having passed a trial on the Isle of Wight.

Other critical unanswered questions about TTI - such as how self-isolation will be enforced - will be announced at Downing Street's press conference tonight.

The Royal Society set up the DELVE multi-disciplinary group - made up of 14 leading experts from the country's top universities - to come up with the exit strategy.

It is tasked with giving input to the Government through SAGE, its scientific advisory group for emergencies.

A Department of Health spokesperson said: 'This modelling makes incorrect assumptions on how long it takes for test results to be received - 84 per cent of tests conducted at our testing sites are returned in under 24 hours. As a result their findings are not accurate.

'More than 2 million people have been tested and the vast majority report no issues with the process.

'The Test and Trace service, which includes dedicated contact tracing staff, public health experts and digital technology, will swiftly get in touch with anyone considered to be at heightened risk of having been exposed to the virus and advise them on the steps they need to take to stop the spread of coronavirus and protect their families, friends, neighbours and work colleagues.

'Everyone needs to play their part in this effort and follow the advice.'

Despite calls from DELVE to speed up COVID-19 testing, British health officials have told companies offering Covid-19 antibody tests to stop processing blood samples from patients in the UK.

The Medicines and Healthcare products Regulatory Agency (MHRA) has confirmed that they have told firms to stop analysing the blood samples that people in the UK submit for testing

The Medicines and Healthcare products Regulatory Agency (MHRA) has confirmed that they have told firms to stop analysing the blood samples that people in the UK submit for testing 

CDC WARNS ANTIBODY TESTS ARE WRONG UP TO HALF THE TIME

Antibody tests for Covid-19 may be wrong up to half of the time, according to updated information from the Centers for Disease Control.

The CDC now warns antibody testing is not accurate enough for it to be used for any policy-making decisions, as even with high test specificity, 'less than half of those testing positive will truly have antibodies'.

It urges caution with the test results as many false positives could lead people to believe they have an immunity to coronavirus and act accordingly.

Health care providers may need to test patients at least twice to give a more accurate reading, the new guidance posted to the CDC website adds.

Antibody studies, also known as seroprevalence research, are considered critical to understanding where an outbreak is spreading and can help guide decisions on restrictions needed to contain it.

There is currently a high level of inaccuracy in the testing, however, caused by how uncommon the virus is within the population.

If the infection has affected only a small number of people tested, it will have a magnified margin of error, the CDC explains.

It means that even a test with more than 90 per cent accuracy can still miss half the cases if only five percent of the population has been infected.

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Private tests to see whether people have already had the disease and recovered are now available from various online pharmacies from around £69.

Superdrug became the first high street retailer to offer the service and numerous websites offer similar tests, including Lloyds Pharmacy.

Now the Government, which has previously been accused of trying to take control of coronavirus testing among the public, has slammed the brakes on private tests.

The Medicines and Healthcare products Regulatory Agency (MHRA) has confirmed it has told firms to stop analysing the blood samples people submit for testing.

At least two labs that process antibody tests using finger-prick samples are known to be affected by the move.

The news comes after Public Health England's testing tsar, Professor John Newton, last week urged people not to pay for private tests and to wait for official ones.

And it comes after US health body the Centers for Disease Control warned antibody tests for Covid-19 may be wrong up to half of the time.

The Government has bought 10million tests from pharmaceutical giant Roche and will start using them on NHS and care staff from this week.

The MHRA and Department of Health officials are expected to meet tomorrow to discuss the issue.

The way antibody tests work is that someone takes their own blood sample, or a medical professional takes it for them, and that is posted off to a lab.

There, qualified technicians analyse the blood to look for antibodies for the coronavirus, which are immune system substances created when someone is infected with the virus.

People then receive a result in which the presence of antibodies - a positive result - indicates they have already had the virus, or the absence that they have not.

The lab analysis stage is now being blocked by the MHRA, MailOnline understands.

It comes as Boris Johnson prepares to announce two households will allowed to meet up from next week.

Ministers are said to have parked proposals for people to be able to mix in social 'bubbles' after expert modelling suggested it could lead to a spike in coronavirus.

They are instead considering a plan which would allow people to see more of their loved ones in person but with social distancing still in place, meaning hugs and handshakes would remain banned.

However, the scheme, which could be rolled out from June 1 at the start of Boris Johnson's second phase of easing, could force households to nominate the friends or family they want to be allowed to see.

Concerns have also been voiced in Cabinet that the rules should not be seen as a 'barbecue clause', allowing for meet-ups in gardens.

Current lockdown rules dictate that you can meet up with one other person from outside your household outdoors as long as you remain two metres apart.

The new plan, first reported by The Times, would allow two households to link up although it is unclear whether everyone in each household would be allowed to attend. This would potentially allow people to see their parents at the same time, for example, something which the existing restrictions prohibit.

It could see people given the green light to invite their partnered household to visit them in a private garden.