States such as Massachusetts and New Jersey have left their app plans in limbo or abandoned them to focus on the bigger picture. “States are struggling to stand up a public health response in general, including plain old vanilla contact tracing,” says Margaret Bourdeaux, a researcher at Harvard Kennedy School. Inadequate testing in some areas has undermined even traditional contact tracing. States that launched large-scale contact-tracing efforts have run into problems ramping up and managing these efforts. Researchers at George Washington University estimate that many states have fewer contact tracers than they need. California, for example, needs more than 30,000 contact tracers to keep up with the virus’s spread, according to the researchers. An NPR survey last month found the state had less than a third of that number.

Contact tracers report difficulties getting people to respond or follow advice to quarantine and seek testing, especially when they can’t also offer resources such as childcare to help. Mistrust of the government, especially among immigrants and lower-income residents, has been compounded by online misinformation about contact tracing.

“It gets to a fundamental thing where some people have started to get disenchanted with the test, trace, isolate programs to control the virus,” says Justin Lessler, a professor of public health at Johns Hopkins University who studies the effectiveness of contact-tracing programs. Rather than give in to that disenchantment, he recommends investing more to make the programs effective. “The challenges here are fast follow-up, trust, and also having quarantine and isolation procedures to help them protect others in their household.”

Digital contact tracing can bolster those efforts, he says, making it easier to reach more people quickly, especially contacts an infected person may not know—like strangers at the store, or colleagues in a different department. But if there’s little support and concerns about digital tracking deter vulnerable groups from adopting the apps, the effort can widen the gaps. “Public trust is everything during a health crisis, so anything that might risk it—especially if the benefit is unclear—is viewed as not worth the effort,” Bourdeaux says.

Seeking Coordination

Early on, it had become clear to some that the US needed a more national response. “We are not Canada,” which has a national health care system and a national contact-tracing app, says Scott Becker, executive director of the Association of Public Health Laboratories (APHL). “It would be a lot simpler if there were a national approach, but that’s not how public health works in the United States.”

In May, a group of officials, including state health officers and technologists at the Centers for Disease Control and Prevention, formed a working group to tackle the problem. One obvious issue was allowing state apps to talk to one another, says Becker, who later joined the discussions. Although Google and Apple offered common technology for exchanging keys over Bluetooth, states initially built their own servers for sending notifications. That posed a problem for interstate tourists and commuters, who might be using apps hooked into different systems. (Plus, having a separate server in every state wasn’t great for security.) So the APHL, which frequently acts as a conduit for public health data between localities and federal agencies, set up a common server for state apps to talk to each other.

A bigger technical issue for states was deciding what they needed in a contact-tracing app and finding someone to build it. Apple and Google’s announcement potentially relieves states of this burden. Instead, they’ll be able to provide some basic information they wish to include in the apps, plus their desired statewide branding, and Apple and Google will generate offerings from a template.

It’s still not clear whether these new apps, named Exposure Notification Express, will prove more successful at slowing the spread of the disease. One big issue: connecting with local health officials, who often oversee traditional contact tracing. “The real friction is the way the contact tracing happens,” says Brookins, the developer of the Care19 app in North Dakota and Wyoming. “It’s the haphazard, heterogenous jurisdictions that’s difficult.”