Test, track, and trace has become a key message in the fight against coronavirus and on Monday we learned more about the third element to this crucial approach.


Contact tracing is seen as one of several possible remedies to help the UK out of lockdown and an app trial is now ready to go, ahead of a full roll-out across the country.

What is contact tracing?

A contact-tracing app is one of the government’s next big areas of focus, part of a wider contact tracing effort, as it tries to find ways to end lockdown while preventing a possible second wave of the virus.

The app uses Bluetooth to keep an anonymous log of everyone you come into close contact with. If one of these people presents symptoms of COVID-19, they will tell the app, which alerts you and everyone else who has been in close proximity.

“Something that is automated, that can work alongside traditional epidemiological contact tracing is potentially going to be of very great use to us,” Professor Jonathan Van-Tam, the deputy chief medical officer for England said.

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What is the coronavirus app like?

Once installed and set up, the app will run in the background, keeping a log of everyone you pass.

Users will need to provide the first part of their postcode and give the app permission to use Bluetooth, as well as its ability to receive notifications.

Bluetooth will need to be kept on.

When a person is feeling unwell, they need to send a report, stating whether they are experiencing a high temperature and a continuous cough, and when these symptoms started.

If it appears they might have the virus, the person will be told to book a test.

How the contact tracing app will work © PA Graphics
© PA Graphics

The information is then uploaded, along with the last 28 days of proximity events, and fed into a complex at-risk algorithm which crunches data such as distance, duration and symptoms.

It will notify only those deemed at risk to isolate for 14 days and ask them to monitor their symptoms.

If the person’s results come back as negative, those who came into contact with them will be told they are able to come out of isolation.

But should the result be positive, the person will be told to self-isolate for seven days, while those who came into contact with them continue self-isolating and book a test of their own if they have the slightest symptom.

With the Isle of Wight trialling the app, does this mean lockdown will end there?

While those on the Isle of Wight will get to use the app first, this does not mean that lockdown will end there any sooner than the rest of the country.

“For the Isle of Wight, all the same safeguards apply, they should still be following all the same social distancing advice,” said Professor John Newton, director of health improvement for Public Health England.

“It’s a staged development, it’s a staged implementation across the country – this is a really important stage, but to be absolutely clear there is no suggestion that we’re asking the Isle of Wight population to take any additional risks, they will be protected further by having access to testing, additional contact tracing and the use of the app.”

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Will the contract tracing app be effective?

Contact tracing is really dependent on several crucial factors – though NHSX boss Matthew Gould has warned it will not be a “silver bullet”.

“The app is exciting, but it’s also not a silver bullet or a standalone solution, it’s part of this wider strategy … it has to be seen as part of this strategy alongside the expansion of testing and human contact tracing,” he said.

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The app is also voluntary, so its effectiveness will rely on the number of people actually using it.

“Uptake is going to be important and so is the compliance with the app and regularly using it over a sustained period of time – and those are unknowns at the moment,” Professor Van-Tam said.

“The market research we’ve done, I think, indicates for the UK that there’s a fairly significant optimism that people will engage with something that is clearly about protecting the NHS.”

How will the NHS coronavirus app affect my privacy?

There have already been concerns raised about privacy on other coronavirus apps, but Google and Apple have announced that they will only approve contact-tracing apps that follow a very specific protocol, making it impossible to associate data with one phone, or person.

It also keeps all data, sent and received, on the users’ phones, unless an infectious person’s “sent” data needs to be uploaded for cross-checking, via encrypted channels. The cross-checking also takes place on users’ phones, not in the central database.

This means that nobody, not even the NHS, has the whole picture. They may know that you have COVID-19 and have uploaded this data, but won’t know the identities of the people whose codes match yours.

Will other symptoms be added?

Yes, this is likely with newer versions of the app as understanding about the virus develops.


What about battery life?

Health Secretary Matt Hancock said the app will use a “form of Bluetooth that conserves power so the app won’t drain your battery”.

How can I protect myself from the coronavirus when shopping?

You’ll have seen signs in your local supermarket advising you to keep two metres from others while moving around the store. This is key to reducing your chances of catching the virus while shopping.

The coronavirus SARS-CoV-2 is spread through respiratory droplets that leave our mouth and nose when we cough, sneeze, or sometimes even talk. The droplets sprayed out by an infected person will contain the virus, which could then enter your body via your mouth, nose or eyes (this is why you shouldn’t be touching your face).

Respiratory droplets don’t usually travel more than one metre, so by keeping two metres from others, you’ll reduce the likelihood of being in the firing line. To make it easier to keep your distance, try to shop during off-peak hours, choose a store that’s limiting the number of people who can be inside at any one time, and use self-checkout if you can.

Keeping your hands clean is the other main thing you can do. If possible, wipe the trolley or basket handles with a disinfectant wipe when you arrive at the store. When you get home, wash your hands or use hand sanitiser before and after unpacking your bags.

A US study found that the coronavirus can survive for up to 24 hours on cardboard, and up to three days on hard, shiny surfaces such as plastic, so wiping down your purchases with a disinfectant spray or a soapy cloth before you put them away is another good habit to get into.

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Alexander McNamaraOnline Editor, BBC Science Focus

Alexander is the former Online Editor at BBC Science Focus.