Apple and Google are building a virus-tracking system. Health officials say it will be practically useless.

_{Photo by Adrien Delforge on Unsplash}

Apple and Google’s announcement last month of a joint effort to track the coronavirus by smartphone sparked a wave of excitement among public health officials hoping the technology would help alert them to potential new infections and map the pandemic’s spread.

But as the tech giants have revealed more details, officials now say the software will be of little use. Due to strict rules imposed by the companies, the system will notify smartphone users if they’ve potentially come into contact with an infected person, but it won’t share any data with health officials or reveal where those meetings took place.

Local health authorities in states like North Dakota, as well as in countries such as Canada and the United Kingdom, say they’ve pleaded with the companies to give them more control over the kinds of information their apps can collect. Without the companies’ help, some worry their contact tracing systems will remain dangerously strained.

But Apple and Google have refused, arguing that letting the apps collect location data or loosening other smartphone rules would...