Apple and Google have announced a new coronavirus contact tracing system to help public health authorities inform potentially infected people - without the need to build their own app.

The move comes as countries across the world have turned to technology to support contact tracing efforts, using bluetooth to keep an anonymous log of those in close proximity.

What has been happening in England?

England’s app has been held back by delays after officials initially opted to develop their own system before later deciding to adopt one devised by the two tech giants designed to improve interoperability.

The latest attempt in England at a contact tracing app is currently going through a trial on the Isle of Wight and the London borough of Newham, with no indication when it may become available nationally.

What have Apple and Google unveiled?

Now the firms have revealed Exposure Notifications Express, which will allow public health authorities to provide a configuration file with basic information and the criteria for triggering an exposure notification.

Once set up, handset holders will be asked if they want to opt in, meaning they will receive an alert if someone they have been near has tested positive for Covid-19.

The latest version of iOS for iPhones will enable the feature without downloading an app in places where public health authorities have signed up while devices using Android will receive a prompt directing them to an app generated by Google.

The NHS and other health bodies can still choose to build their own apps without Exposure Notifications Express, which Apple and Google said they will continue to support.

Professor Christophe Fraser, from the department of health at Oxford University, said: “We’ve been exploring different app uptake levels for some time in the UK and we’re really pleased to see that contact tracing apps in the UK and the USA have the potential to meaningfully reduce the number of cases, hospitalisations and deaths at all levels of app uptake across the population.

“For example, we estimate that a well-staffed manual contact tracing workforce combined with 15 per cent uptake could reduce infections by 15 per cent and deaths by 11 per cent.”

Who will be the first to try the feature?

People living in US states Maryland, Nevada, Virginia and Washington DC will be the first to try the feature.

What have Apple and Google said?

“As the next step in our work with public health authorities on exposure notifications, we are making it easier and faster for them to use the exposure notifications system without the need for them to build and maintain an app,” Apple and Google said in a joint statement.

“Exposure Notifications Express provides another option for public health authorities to supplement their existing contact tracing operations with technology without compromising on the project’s core tenets of user privacy and security.

“Existing apps using the exposure notification API will be compatible with Exposure Notifications Express and we are committed to supporting public health authorities that have deployed or are building custom apps.”