The technology is designed to slow the spread of coronavirus by tracking who a person has been in close contact with. The technology uses a Bluetooth-based system that stores data on people's phones, not a central database. When someone officially tests positive for Covid-19, the system can send a notification to anyone who was recently near that person, telling them to contact their local health authority and get medical advice and a coronavirus test.
Apple and Google won't make the actual contact tracing apps, government health bodies will. 22 countries and some US states have requested and received access to the Apple-Google technology, the companies said. The technology is included in iPhone and Android updates released to the public on Wednesday. While several countries in Europe have said they will use the system, these are the first U.S. states to commit.
Apple and Google technology will be used in North Dakota's CARE19 app, and the South Carolina SC-Safer-Together app, according to statements distributed by the companies. Alabama's state health officer said that the state is "harnessing technology to accelerate exposure notification to slow the spread of COVID-19 so that we can all be safe together" in a statement.
"North Dakota is excited to be among the first states in the nation to utilize the exposure notification technology built by Apple and Google to help keep our citizens safe," North Dakota governor Doug Burgum said in a statement.
The Apple and Google approach was designed to protect users' privacy and limit the use of personal information in digital contact tracing.
The companies won't allow apps built with their technology to use GPS data, which can pinpoint a user's location, and won't allow governments to turn them on silently, company representatives said. The companies also say they will restrict governmental authorities to collecting the minimum amount of data necessary, and nobody will be able to use the data for advertising or other uses.
Without using the Apple and Google system, apps will have difficulty using Bluetooth to trace contacts, because both iOS and Android restrict the use of Bluetooth in the background. Apps that haven't used the Apple-Google system, like Singapore's Trace Together app, have run into battery life and usability issues.
The biggest challenge for these apps going forward is adoption. The more phones that opt-in to the system, the more successfully it can detect how the virus spreads. Apple and Google say that getting the public to trust the apps and opt-in is critical to the effort.
But some states, like Utah, have taken a different approach to digital contact tracing in which users can share specific location data with human contact tracers -- health employees who typically call up people who have tested positive or are at high-risk for contracting the virus. They argue that using more location data and a centralized approach will give more tools to public health departments than the anonymous Apple-Google system.
Some governments have changed their internal approaches to adopt the Apple-Google system. An early version of the North Dakota Care19 app used anonymized GPS location data and didn't use the Apple-Google Bluetooth technology, for example.