Covid apps went through the hype cycle. Now, they might be ready to work.

Jen Tracy, 36, was sick of hearing people bickering about how to respond to the coronavirus pandemic and last week, New Jersey offered an alternative she liked better: a smartphone app.

Tracy, who lives in Pine Hill, New Jersey, became one of the early adopters of an app the state rolled out to try to slow the spread of Covid-19. The app displays statistics, such as the percentage of people who are reporting symptoms, and maybe more importantly, it’s designed to alert people if they’ve been near someone else who’s tested positive.

“We are in this together. Let’s stop bickering and start keeping each other safe,” she said.

The app and similar ones in other states are the culmination of an effort that’s been brewing since early this year, when software engineers first thought up the idea of creating apps to try to warn people about exposure to the coronavirus.

Early versions launched in the spring in countries such as Singapore, but development stalled in the United States while researchers worked to make apps that would protect people’s privacy and state officials focused on fighting the first wave of Covid-19 infections. In June, New Jersey Gov. Phil Murphy said digital alerts weren’t something his state was working on.

But New Jersey and other states are warming up to the technology. The apps use the Bluetooth sensors in smartphones to determine possible exposure and then send anonymous notifications, all without creating the kind of government database that would alarm privacy advocates.

If a user of the app spends significant time near someone else who also uses the app and who later tests positive, they should get a push alert on their phone advising them of possible exposure and suggesting a test and some time in quarantine. The names of people who test positive aren’t revealed.

“What it’s trying to do is to break the chain of transmission as best as we can,” said Larry Breen, chief commercial officer of NearForm, a software company that has helped various governments build their apps.

“It’s about getting citizens on board and giving them the tools to protect themselves, their neighbors and their fellow citizens,” he said.

More than 105,000 people had downloaded New Jersey’s app as of Monday afternoon, five days after its launch. That’s only about 1.2 percent of New Jersey’s population, but the state hopes to grow the number through social media and outreach to colleges, businesses and others, Nancy Kearney, a spokesperson for the state Department of Health, said.

In New York, which launched its app the same day as New Jersey on Thursday, about 400,000 people had downloaded the app as of Monday morning, Laura Montross, a spokesperson for Gov. Andrew Cuomo, said.

So far, 10 states have launched apps to alert people of possible exposure, according to the Linux Foundation Public Health, a nonprofit that provides software and other assistance to public health authorities. Other states including California and Arizona are in testing phases, CNBC reported.

Employers, universities and private companies have deployed apps of their own to help with exposure notification or contact tracing, but the state-run apps are different in a couple of key ways.

One difference is that the state-run apps run on top of tools developed by Apple and Google. The two tech companies formed an unusual partnership in April to enable states to create apps in a way that does not track people’s movements, and the companies are allowing only one official app per state in the U.S.

A smartphone app built for the state of Utah displaying coronavirus test sites.Lindsay Whitehurst / AP file

Virginia, the first state to use the Apple-Google technology, launched its app in August.

Also, apps developed by state governments are now interoperable, so they can work with each other even while people are traveling across state lines. That’s because the Association of Public Health Laboratories set up a national server in July to host the system’s keys, which are randomly generated numbers.

“You no longer have to worry about interoperability, because it’s there by default,” said Jenny Wanger, head of the Implementer’s Forum at the foundation.

New York, New Jersey, Delaware and Pennsylvania all have apps now, forming the start of an East Coast corridor.

Wanger said it’s relatively easy now for any state to develop its own app for digital alerting, compared with several months ago when some states were skeptical, because the computer code is open-source and there are experienced vendors available to help. Other charities such as Bloomberg Philanthropies have helped cover the cost.

In Ireland, which launched its tracing app in July, adoption is around a third of the population, Breen said. But he and other experts said even a small level of adoption can be useful as part of an overall strategy that tries various ways to slow the advance of Covid-19.

In one study released last month, researchers from academia and the tech industry said that even if only 15 percent of a given population participated, digital alerts could reduce infections by 8 percent and deaths by 6 percent, complementing more traditional forms of contact tracing by human investigators.

source: nbcnews.com