How Effective Are Contact Tracing Apps?

This article is part of Privacy in the Pandemic, a Future Tense series. But we still don’t really know how effective contact tracing apps actually are—particularly in societies that don’t already have a vast surveillance infrastructure. Iceland’s success in managing COVID-19 might instead be attributed to other factors, including the country’s early testing of high-risk individuals before it even confirmed its first case, wide-scale testing in the months since, that robust manual contact tracing system, and geographic isolation. In an April blog post, he wrote, “If you ask me whether any Bluetooth contact tracing system deployed or under development, anywhere in the world, is ready to replace manual contact tracing, I will say without qualification that the answer is, No.” There is simply too much critical information that an automated system can’t access, Bay argued. That article’s authors argued that contact tracing technology often doesn’t account for barriers as basic as walls, or personal protections such as masks, and thus would flag individuals unlikely to have been infected.