By Dennis Thompson
MONDAY, April 27, 2020 (HealthDay News) — Governors preparing to relax social distancing orders and reopen their economies are about to make a dire mistake that could cause COVID-19 cases to surge in their states, infectious disease experts warn.
The United States’ ability to contain future COVID-19 outbreaks rests on its ability to test hundreds of thousands daily for the virus, and the country is nowhere near that capacity, researchers say.
The United States needs at least 500,000 COVID-19 virus tests performed daily to even have a hope of safely reopening, more than triple the capacity officials have been able to achieve, Dr. Ashish Jha, director of the Harvard Global Health Institute, said during a media briefing on Wednesday.
Others have estimated even more testing is needed, on the order of 10 to 20 million tests daily, but Jha thinks the country could get by with a half million tests daily if that’s coupled with vigorous public health efforts to trace contacts and isolate the infected.
“Testing is really at the center of the entire strategy for how we keep the virus at bay as we reopen the economy,” Jha said.
For the past month, the United States has plateaued at around 150,000 tests a day, Jha said.
The White House has publicly resisted the notion that not enough testing is taking place, but Jha said privately he’s heard otherwise from top COVID-19 task force members.
“Despite the comments of the president and the vice president, there is broad agreement within the administration that we substantially need to scale up testing, that 150,000 tests per day are not nearly enough to bring caseloads down now, and it certainly is not going to be enough once we begin to open up our economy,” Jha said.
Federal intervention is going to be needed to coordinate testing efforts between states and set clear guidelines that could safely steer states, said Jha and Dr. Michael Gunn, a professor of immunology at Duke University School of Medicine, in Durham, N.C.
“The thing the federal government could best do right now is come up with a plan,” Gunn said. “The American people are very willing to sacrifice for the common good, but we need a coherent plan that everyone can follow.”
Supply far below the demand
There are two types of COVID-19 testing — ones that look for active virus in people’s blood, and others that look for antibodies that infected people have developed to the virus, said Jill Taylor, director of the Wadsworth Center at the New York State Public Health Department.
Active virus tests are the ones that will be needed to help safely relax social distancing rules, Taylor and Jha said at the media briefing. At this point, antibody tests aren’t particularly helpful or accurate.
Nearly 40 tests are now on the market to look for active viral infection, most of which rely on laboratory analysis of nasal swabs or saliva, Taylor said.
Unfortunately, the haphazard governmental response to the COVID-19 pandemic has prevented viral testing from ramping up as much as is needed to head off future outbreaks, the experts said.
Shortages of swabs and other materials used in testing have caused most labs to use several different COVID-19 tests at once to keep churning out results, Taylor said.
Taylor noted that her lab currently uses three different tests, so that a shortage affecting one type of test will not stop them from continuing to process samples.
“This has been a problem that has affected all of us for many weeks now,” Taylor said. “Having multiple platforms available is an absolute essential.”
Beyond that, Jha added, the states simply aren’t casting a wide enough testing net to be able to get ahead of future outbreaks.
Lots of hidden cases
About 20% of Americans tested are positive for COVID-19, a strong indication that not nearly enough people are being tested for active infection, Jha said. The World Health Organization has recommended if a nation’s test positivity is over 10%, it’s probably not testing enough people to provide effective infection control.
By comparison, South Korea’s positive rate is around 3%, and Germany’s is about 7%.
The problem is that states have not adapted as the pandemic has evolved, Jha explained.
“The states put in highly restrictive policies about who’s eligible for testing five or six weeks ago when tests were scarce. You were only allowed to do testing of hospitalized patients who were very ill,” Jha said. “As testing has been expanded in those states, those guidelines have either not been updated or not been effectively communicated to physicians,” he noted.
“There are many states where there is enough testing capacity and excess capacity, but people are not sending samples in,” Jha concluded.
The federal government will need to step in as a testing coordinator if the nation is going to reopen its economy without an overwhelming surge in COVID-19 cases, Jha said. The feds could help by making sure that states share resources so that everyone has enough supplies to perform adequate testing.
“It’s hard to see, for me, that 50 states all competing for testing against each other is going to be the solution to get us to where we need to be,” Jha said.
Uncertainly over immunity
At this point, antibody tests are beside the point because even if they are accurate — which is not certain — no one knows what their results mean.
There’s no way to tell if people already infected with the coronavirus are now immune, even if they carry antibodies, the experts said.
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And even if that is the case, far too few people have contracted the virus to create any level of herd immunity, said Dr. Georges Benjamin, executive director of the American Public Health Association.
A recent two-day antibody test of 800 people in Los Angeles revealed that about 4% carried antibodies for COVID-19, Benjamin said.
This result implies that COVID-19 has been much more infectious than public health case reports have noted.
Based on a 4% infection rate, as many as 442,000 adults in the L.A. area have been infected — a number 55 times higher than the 7,994 confirmed cases of COVID-19 reported to the county by the time the antibody study took place, Benjamin said.
Worse, a 4% infection rate is well below the 50% to 70% exposure needed to confer herd immunity, Benjamin and Jha said.
“It’s hard to imagine how we open up our economy with 2, 3, 4% of people who are potentially immune,” Jha said. “And, of course, having antibodies is not equal to actually being immune.”
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SOURCES: Michael Gunn, M.D., professor, immunology, Duke University School of Medicine, Durham, N.C; April 22, 2020 briefing with: Ashish Jha, M.D., MPH, director, Harvard Global Health Institute, Boston; Jill Taylor, Ph.D., director, Wadsworth Center, New York State Public Health Department; and Georges Benjamin, M.D., executive director, American Public Health Association