By Rolfe Winkler
Covid-19 contact-tracing apps from Apple Inc. and Google are
coming to more states, along with evidence that they can help slow
infections as long as enough people use them.
Fourteen states and Washington, D.C., have recently adopted the
"exposure notification" technology the companies built into their
smartphone operating systems -- Big Tech's most significant
contribution to the fight against Covid-19. California, and other
states are piloting the technology and could release it soon. It
lets people who have tested positive for Covid-19 alert others they
have previously been in close contact with that they should take
precautions or get a test.
As case counts explode and a nationwide rollout of vaccines
remains months away, epidemiologists say the technology can help
slow the virus's spread -- if widely used and fast testing is
broadly available. Yet many of the millions of Americans who have
access so far are skeptical, suspicious or simply unaware of
That has been the struggle in Virginia, which in early August
became the first state to roll out an exposure notification app.
Three months later, downloads of the app, known as Covidwise,
amounted to roughly a 10th of Virginia's population of about 8.5
Politicization of the virus has hampered efforts to increase the
app's adoption, said Jeff Stover, executive adviser to Virginia's
health commissioner who is in charge of Covidwise. "That doesn't
help convince Virginians to download and run an exposure
notification app that is run by the government," he said.
Nearby Washington, D.C., offers some hope for public
participation. A third of the district's population, including
commuters, had activated the smartphone function less than a month
after it became available, thanks to a tweak from Apple and Google
that allows public-health authorities to send push alerts that the
technology is available. Colorado and Maryland also have seen fast
uptake after sending push alerts.
Mr. Stover said Virginia plans an update in a few weeks so it
can send alerts and allow Covidwise to work with versions of the
technology being run elsewhere, including nearby Washington, D.C.,
Many European countries rolled out apps based on the
Apple-Google technology this summer. In Switzerland, 1,695 people
called a special hotline after receiving a notification in the
SwissCovid app that they had been exposed and 65 people who tested
positive credited a notification from the app for encouraging them
to get a test, according to a paper published in September.
Armin Betschart, an insurance executive who lives in a Zurich
suburb, remembers a Monday afternoon in September when his
SwissCovid app warned him of a possible exposure. The notification
came a few hours before a family member called with news of a
positive test, Mr. Betschart said.
He tested negative but believes if he had been positive, and the
exposure came from a stranger, the app would've been his only
warning that he might be contagious before the onset of
Despite the promised benefits, few in the U.S. have downloaded
the state-based apps or otherwise enabled the technology on their
phones. About 800,000 people have downloaded Virginia's app to
date, Mr. Stover said. New York's app has been downloaded roughly
700,000 times and Pennsylvania's 500,000 times, according to data
from research firm Sensor Tower.
If few people download the apps, their impact will be limited.
With about 10% of Virginians using Covidwise, that means there is a
10% chance the people they bump into are using it as well, so only
1% of close contacts are theoretically logged, limiting the
potential number of exposure notifications that can be sent.
"If I were to test positive, it would be good to know that I had
a way to alert people that I have no way to contact directly," said
Kelly DeLucia, who lives in Yorktown, Va., and uses Covidwise. "I
think that if we could reach critical mass with the number of
users, it could be a real tool to help contain the spread."
Virginia's governor, Ralph Northam, has promoted the app at news
conferences. When he came down with Covid-19 in late September,
three of his staff members received alerts that they had been
exposed. All three had been traveling with the governor, so they
were aware of their exposure before receiving the smartphone alert,
according to his press secretary, Alena Yarmosky, who was one of
It was a real-world test that demonstrated the technology works,
Ms. Yarmosky said, adding that it may have alerted others the
governor came into contact with who didn't know about his positive
Other Virginians say they are skeptical of the technology.
Kellen MacBeth, who works from home in Arlington, said he sees why
people in high-risk jobs might want to use the app, but he doesn't
see why he would need it since he didn't leave his house for three
months early in the pandemic and has since limited his contacts to
a few close friends. He tries to avoid downloading apps to protect
his privacy, he said.
The Virginia Department of Health can see how often Covidwise is
downloaded, and it has sent 116 notifications a day, on average,
since late August. But it doesn't know who has been notified or
where they live. That information could help public-health
authorities direct resources to hot spots, but Apple and Google
designed the system to obscure it to protect privacy, the companies
Two local Virginia Facebook groups offer a glimpse of how
opinions about Covidwise, much like masks, are split along
political lines. One of the groups is for residents of Arlington
County, which mostly supported Joe Biden, and the other for
residents of Montpelier in Hanover County, which voted more often
for Donald Trump. A post about Covidwise in the Arlington County
group elicited mostly positive comments that the app could help
stop the virus's spread. A similar post in the Montpelier group
drew more negative comments, suggesting the app would invade
Google and Apple say the technology protects people's privacy.
The companies posted the source code publicly so that claim can be
verified, they say.
Some Virginians don't use Covidwise because they aren't aware of
it. Each week, hundreds of grocery store cashiers, construction
workers and others facing high risk show up to get free Covid tests
at the Arlington Mill Community Center, where there were no signs
promoting the app. A patient exiting the center after a recent
visit told a Wall Street Journal reporter that staff didn't mention
Mr. Stover said Virginia has a $1.5 million budget to promote
Apple and Google hope they can solve the problem of anemic
adoption with a new release that lets states avoid the time and
expense of developing their own apps and allows them to send push
alerts directly to smartphone users to enable exposure
Washington, D.C., began sending out push alerts to residents and
commuters on Oct. 20. By Nov. 18, 384,000 people, roughly a third
of its workday population, had activated the technology on their
smartphones. Maryland and Colorado also sent push alerts and have
seen almost 20% of their population activate the technology within
a month of launch.
Wider adoption of exposure notification technology is of little
use if other links in the chain break. Switzerland looked like a
success story in early September, but that was before case counts
jumped in October, said Marcel Salathé, head of digital
epidemiology for the Swiss government's Covid-19 task force. Mr.
Salathé wrote a paper showing early, promising data for the
SwissCovid app. Testing can take days and getting the code
sometimes even longer, delaying notifications to the point of
uselessness, he said.
"These systems can make quite a difference, if they are set up
properly, " said Mr. Salathé. "It's a shame when they aren't given
--Aruna Viswanatha contributed to this article.
Write to Rolfe Winkler at email@example.com
(END) Dow Jones Newswires
November 21, 2020 11:14 ET (16:14 GMT)
Copyright (c) 2020 Dow Jones & Company, Inc.