Those paying close attention to the daily press briefings may remember that, on March 26, Jenny Harries, the Deputy Chief Medical Officer, told reporters: “Although we still do some contact tracing and testing, for example in high-risk areas like prisons and care homes, that is not an appropriate mechanism as we go forward”.

So some will be surprised by Matt Hancock’s briefing yesterday, in which he appeared to contradict her words – announcing that a “large-scale” operation was underway – in order to ramp up the country’s contact tracing capabilities.

Was this a U-turn? It is arguably the third time that the UK (whether the Government, health authorities, or both) has changed its mind on rolling out this strategy, which involves detecting those infected with Coronavirus and their contacts, so as to control the spread.

Indeed, in the initial phases of this outbreak (for six weeks between January and March), Public Health England (PHE) used contact tracing to track COVID-19. But this approach was abandoned on March 12, on the basis that it was no longer effective, due to the escalating rate of community transmissions. 

What explains the Government’s new direction? Well for one, its options are rather limited; herd immunity – whether it was ever properly considered, or not – is now unsaleable as a strategy. And after going into lockdown mode, the Government has been under huge pressure to produce an exit strategy – exacerbated by Nicola Sturgeon, who has released one for Scotland.

Conservatives have been reticent to produce anything similar, instead telling the public that five tests will be used to determine what’s next in the UK’s Coronavirus approach. But contact tracing at least offers a glimmer of hope to the public that freedom is not so far away. It acts as a complementary technique – allowing governments to slowly reopen their economies while keeping a close eye on how the virus is spreading. Without it, they are fighting blind – with no idea of who’s taking the bug where.

The plan to roll out contact tracing also follows Germany, South Korea and Singapore, which have all used it with various degrees of success to manage transmission of the virus. The World Health Organisation has claimed it should be “the backbone of the response in every country”. So perhaps it’s no wonder we are finally at this point.

The UK’s programme has two major components.

One is the recruitment of human contact tracers to identify and help isolate people with new symptoms – and any others that they have infected. These recruits will give practical advice to patients who are self-isolating, as well as obtaining details of places that they’ve been to and who they’ve been around.

Currently, PHE has 290 such recruits, but ministers want to ramp this up to 18,000 contact tracers, including 3,000 health professionals, with council staff and civil servants drafted in to carry out these jobs.

The next part of the strategy involves technology. The NHS is developing a Bluetooth app for smartphones, titled NHSX, which allows members of the public to report when they’re feeling unwell.

If COVID-19 is suspected they will be sent a home testing kit, and if it comes back positive, the app will automatically alert people also using the app who’ve been in close quarters with the patient.

The advantages to Bluetooth technology is that it can detect others with the same app – while keeping everyone’s location and identity anonymous. All that is communicated is whether the other person has had the Coronavirus.

There will be some teething issues, one imagines, with the project.

For starters, the Government will have to encourage large numbers of the public to download the app. It has been estimated that 60 per cent of the population needs to use it in order for it to have an effective impact.

This will no doubt be contingent on factors, such as how many people have smartphones, how technologically savvy the Brits are – and how much they want to comply with the Government’s suggestion. All unknowns.

Some have also had concerns about their privacy being invaded, although the Government’s approach looks fairly polite compared to South Korea – where interviews, GPS phone tracking, credit-card records and surveillance camera footage was used for contact-tracing.

Lastly, one of the most critical questions will be whether 18,000 staff are enough to roll out the project. It sounds impressive, but some scientists say we need 100,000 contact tracers. One suspects volunteers will eventually be called in to help – as there will be increasing cries from the media as to whether we have enough.

Even so, along with massive increases in testing, it is an important step forward – in conquering the disease.  And a third significant change of course.