The new plan unifies some of the behind-the-scenes work of sending exposure notifications. In the original scheme, state health authorities were responsible for setting up servers to send exposure alerts to people who had been near others who had tested positive for Covid-19. Different states, different servers. That meant apps in different states couldn’t easily talk to each other. Now that will be handled by a central server, operated by the Association of Public Health Laboratories. Some existing apps using the Apple-Google system, including those recently released in Wyoming and North Dakota, are already designed to communicate with the association’s server—and thus with other apps.
The move wasn’t entirely unexpected. When Apple and Google announced their digital tracing plans, they told WIRED they planned to issue an update in June that would incorporate elements of the system into their phone operating systems. So long as people opted in to