Security workers walk with detection dogs in an airport terminal.

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Asher is eccentric and inquisitive. He loves an audience, likes keeping busy, and howls to be let through doors. He is a six-year-old working Cocker Spaniel, who, with five other furry colleagues, has now been trained to sniff body odor samples from humans to detect COVID-19 infections.

As the Delta variant and other new versions of the SARS-CoV-2 virus emerge, public health agencies are once again recommending masking while employers contemplate mandatory vaccination. While PCR tests remain the "gold standard" of COVID-19 tests, they can take hours to flag infections. To accelerate the process, scientists are turning to a new testing tool: sniffer dogs.

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Puja Changoiwala
Puja Changoiwala is an award-winning journalist and author based in Mumbai. She writes about the intersections of gender, crime, technology, social justice and human rights in India. She tweets @cpuja.

Bobby Brooke Herrera, the co-founder and CEO of e25Bio, demonstrates the company's rapid paper-strip test for detecting the coronavirus.

(Screenshot of demonstration at https://rb.gy/j4hsfc)

You're lying in bed late at night, the foggy swirl of the pandemic's 8th month just beginning to fall behind you, when you detect a slight tickle at the back of your throat.

"If half of people choose to use these tests every other day, then we can stop transmission faster than a vaccine can."

Suddenly fully awake, a jolt of panicked electricity races through your body. Has COVID-19 come for you? In the U.S., answering this simple question is incredibly difficult.

Now, you might have to wait for hours in line in your car to get a test for $100, only to find out your result 10-14 days later -- much too late to matter in stopping an outbreak. Due to such obstacles, a recent report in JAMA Internal Medicine estimated that 9 out of 10 infections in the U.S. are being missed.

But what if you could use a paper strip in the privacy of your own home, like a pregnancy test, and find out if you are contagious in real time?

e25 Bio, a small company in Cambridge, Mass., has already created such a test and it has been sitting on a lab bench, inaccessible, since April. It is an antigen test, which looks for proteins on the outside of a virus, and can deliver results in about 15 minutes. Also like an over-the-counter pregnancy test, e25 envisions its paper strips as a public health screening tool, rather than a definitive diagnostic test. People who see a positive result would be encouraged to then seek out a physician-administered, gold-standard diagnostic test: the more sensitive PCR.

Typically, hospitals and other health facilities rely on PCR tests to diagnose viruses. This test can detect small traces of genetic material that a virus leaves behind in the human body, which tells a clinician that the patient is either actively infected with or recently cleared that virus. PCR is quite sensitive, meaning that it is able to detect the presence of a virus' genetic material very accurately.

But although PCR is the gold-standard for diagnostics, it's also the most labor-intensive way to test for a virus and takes a relatively long time to produce results. That's not a good match for stopping super-spreader events during an unchecked pandemic. PCR is also not great at identifying the infected people when they are most at risk of potentially transmitting the virus to others.

That's because the viral threshold at which PCR can detect a positive result is so low, that it's actually too sensitive for the purposes of telling whether someone is contagious.

"The majority of time someone is PCR positive, those [genetic] remnants do not indicate transmissible virus," epidemiologist Michael Mina recently Tweeted. "They indicate remnants of a recently cleared infection."

To stop the chain of transmission for COVID-19, he says, "We need a more accurate test than PCR, that turns positive when someone is able to transmit."

In other words, we need a test that is better at detecting whether a person is contagious, as opposed to whether a small amount of virus can be detected in their nose or saliva. This kind of test is especially critical given the research showing that asymptomatic and pre-symptomatic people have high viral loads and are spreading the virus undetected.

The critical question for contagiousness testing, then, is how big a dose of SARS-CoV-2, the virus that causes COVID, does it take to infect most people? Researchers are still actively trying to answer this. As Angela Rasmussen, a coronavirus expert at Columbia University, told STAT: "We don't know the amount that is required to cause an infection, but it seems that it's probably not a really, really small amount, like measles."

Amesh Adalja, an infectious disease physician and a senior scholar at the Johns Hopkins University Center for Health Security, told LeapsMag: "It's still unclear what viral load is associated with contagiousness but it is biologically plausible that higher viral loads, in general, are associated with more efficient transmission especially in symptomatic individuals. In those without symptoms, however, the same relationship may not hold and this may be one of the reasons young children, despite their high viral loads, are not driving outbreaks."

"Antigen tests work best when there's high viral loads. They're catching people who are super spreaders."

Mina and colleagues estimate that widespread use of weekly cheap, rapid tests that are 100 times less sensitive than PCR tests would prevent outbreaks -- as long as the people who are positive self-isolate.

So why can't we buy e25Bio's test at a drugstore right now? Ironically, it's barred for the very reason that it's useful in the first place: Because it is not sensitive enough to satisfy the U.S. Food and Drug Administration, according to the company.

"We're ready to go," says Carlos-Henri Ferré, senior associate of operations and communications at e25. "We've applied to FDA, and now it's in their hands."

The problem, he said, is that the FDA is evaluating applications for antigen tests based on criteria for assessing diagnostics, like PCR, even when the tests serve a different purpose -- as a screening tool.

"Antigen tests work best when there's high viral loads," Ferré says. "They're catching people who are super spreaders, that are capable of continuing the spread of disease … FDA criteria is for diagnostics and not this."

FDA released guidance on July 29th -- 140 days into the pandemic -- recommending that at-home tests should perform with at least 80 percent sensitivity if ordered by prescription, and at least 90 percent sensitivity if purchased over the counter. "The danger of a false negative result is that it can contribute to the spread of COVID-19," according to an FDA spokesperson. "However, oversight of a health care professional who reviews the results, in combination with the patient's symptoms and uses their clinical judgment to recommend additional testing, if needed, among other things, can help mitigate some risks."

Crucially, the 90 percent sensitivity recommendation is judged upon comparison to PCR tests, meaning that if a PCR test is able to detect virus in 100 samples, the at-home antigen test would need to detect virus in at least 90 of those samples. Since antigen tests only detect high viral loads, frustrated critics like Mina say that such guidance is "unreasonable."

"The FDA at this moment is not understanding the true potential for wide-scale frequent testing. In some ways this is not their fault," Mina told LeapsMag. "The FDA does not have any remit to evaluate tests that fall outside of medical diagnostic testing. The proposal I have put forth is not about diagnostic testing (leave that for symptomatic cases reporting to their physician and getting PCR tests)....Daily rapid tests are not about diagnosing people and they are not about public health surveillance and they are not about passports to go to school, out to dinner or into the office. They are about reducing population-level transmission given a similar approach as vaccines."

A reasonable standard, he added, would be to follow the World Health Organization's Target Product Profiles, which are documents to help developers build desirable and minimally acceptable testing products. "A decent limit," Mina says, "is a 70% or 80% sensitivity (if they truly require sensitivity as a metric) to detect virus at Ct values less than 25. This coincides with detection of the most transmissible people, which is important."

(A Ct value is a type of measurement that corresponds inversely to the amount of viral load in a given sample. Researchers have found that Ct values of 13-17 indicate high viral load, whereas Ct values greater than 34 indicate a lack of infectious virus.)

"We believe this should be an at-home test, but [if FDA approval comes through] the first rollout is to do this in laboratories, hospitals, and clinics."

"We believe that population screening devices have an immediate place and use in helping beat the virus," says Ferré. "You can have a significant impact even with a test at 60% sensitivity if you are testing frequently."

When presented with criticism of its recommendations, the FDA indicated that it will not automatically deny any at-home test that fails to meet the 90 percent sensitivity guidance.

"FDA is always open to alternative proposals from developers, including strategies for serial testing with less sensitive tests," a spokesperson wrote in a statement. "For example, it is possible that overall sensitivity of the strategy could be considered cumulatively rather than based on one-time testing….In the case of a manufacturer with an at-home test that can only detect people with COVID-19 when they have a high viral load, we encourage them to talk with us so we can better understand their test, how they propose to use it, and the validation data they have collected to support that use."

However, the FDA's actions so far conflict with its stated openness. e25 ended up adding a step to the protocol in order to better meet FDA standards for sensitivity, but that extra step—sending samples to a laboratory for results—will undercut the test's ability to work as an at-home screening tool.

"We believe this should be an at-home test, but [if FDA approval comes through] the first rollout is to do this in laboratories, hospitals, and clinics," Ferré says.

According to the FDA, no test developers have approached them with a request for an emergency use authorization that proposes an alternate testing paradigm, such as serial testing, to mitigate test sensitivity below 80 percent.

From a scientific perspective, antigen tests like e25Bio's are not the only horse in the race for a simple rapid test with potential for at-home use. CRISPR technology has long been touted as fertile ground for diagnostics, and in an eerily prescient interview with LeapsMag in November, CRISPR pioneer Feng Zhang spoke of its potential application as an at-home diagnostic for an infectious disease specifically.

"I think in the long run it will be great to see this for, say, at-home disease testing, for influenza and other sorts of important public health [concerns]," he said in the fall. "To be able to get a readout at home, people can potentially quarantine themselves rather than traveling to a hospital and then carrying the risk of spreading that disease to other people as they get to the clinic."

Zhang's company Sherlock Biosciences is now working on scaled-up manufacturing of a test to detect SARS CoV-2. Mammoth Biosciences, which secured funding from the National Institutes of Health's Rapid Acceleration of Diagnostics program, is also working on a CRISPR diagnostic for SARS CoV-2. Both would check the box for rapid testing, but so far not for at-home testing, as they would also require laboratory infrastructure to provide results.

If any at-home tests can clear the regulatory hurdles, they would also need to be manufactured on a large scale and be cheap enough to entice people to actually use them. In the world of at-home diagnostics, pregnancy tests have become the sole mainstream victor because they're simple to use, small to carry, easy to interpret, and costs about seven or eight dollars at any ubiquitous store, like Target or Walmart. By comparison, the at-home COVID collection tests that don't even offer diagnostics—you send away your sample to an external lab—all cost over $100 to take just one time.

For the time being, the only available diagnostics for COVID require a lab or an expensive dedicated machine to process. This disconnect could prolong the world's worst health crisis in a century.

"Daily rapid tests have enormous potential to sever transmission chains and create herd effects similar to herd immunity," Mina says. "We all recognize that vaccines and infections can result in herd immunity when something around half of people are no longer susceptible.

"The same thing exists with these tests. These are the intervention to stop the virus. If half of people choose to use these tests every other day, then we can stop transmission faster than a vaccine can. The technology exists, the theory and mathematics back it up, the epidemiology is sound. There is no reason we are not approaching this as strongly as we would be approaching vaccines."

--Additional reporting by Julia Sklar

Kira Peikoff
Kira Peikoff is the editor-in-chief of Leaps.org. As a journalist, her work has appeared in The New York Times, Newsweek, Nautilus, Popular Mechanics, The New York Academy of Sciences, and other outlets. She is also the author of four suspense novels that explore controversial issues arising from scientific innovation: Living Proof, No Time to Die, Die Again Tomorrow, and Mother Knows Best. Peikoff holds a B.A. in Journalism from New York University and an M.S. in Bioethics from Columbia University. She lives in New Jersey with her husband and son.
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Dr. Andrew Brooks of RUCDR Infinite Biologics holds up a saliva sample.

(Photo credit: Nick Romanenko/Rutgers, The State University of New Jersey)

The patient tilts back her head and winces as the long swab stick pushes six inches up her nose. The tip twirls around uncomfortably before it's withdrawn.

"Our saliva test can detect the virus in asymptomatic and pre-symptomatic cases."

A gloved and gowned healthcare worker wearing a face shield and mask tells the patient that she will learn whether she is positive for COVID-19 as soon as the lab can process her test.

This is the typical unpleasant scenario for getting a coronavirus test. But times are rapidly changing: Today, for the first time, the U.S. Food and Drug Administration cleared one company to sell saliva collection kits for individuals to use at home.

Scientists at the startup venture, RUCDR Infinite Biologics at Rutgers University in New Jersey, say that saliva testing offers an easier, more useful alternative to the standard nasal swab.

"Our saliva test can detect the virus in asymptomatic and pre-symptomatic cases," said Dr. Andrew Brooks, chief operating officer at RUCDR.

Another venture, Darwin BioSciences in Colorado, has separately developed an innovative method of testing saliva for the coronavirus that causes COVID-19.

Saliva testing can allow earlier detection to identify people who may not know they are contagious, say scientists at both companies. In addition, because patients spit into a tube or cup, saliva testing is safer for healthcare workers than taking swabs. This frees up scarce personal protective equipment (PPE) for use elsewhere. Nasal swabs themselves have been in scarce supply.

Saliva testing, if it becomes widespread, potentially could mean opening society sooner. The more ubiquitous testing becomes across the population, experts say, the more feasible it becomes for public health officials to trace and isolate contacts, especially of asymptomatic cases. Testing early and often will be essential to containing emerging hot spots before a vast outbreak can take root.

Darwin Biosceiences is preparing to seek an FDA Emergency Use Authorization (EUA) this month for its patented "CoVScreen" testing system, which potentially could be available to labs nationally by mid-summer.

Meanwhile, Infinite Biologics will now begin selling kits to consumers for home collection, upon order by a physician. The FDA said that the company's saliva test was as accurate as the nasal swab method used by health care professionals. An FDA summary documenting the company's data reported: "There was 100% positive and negative agreement between the results obtained from testing of saliva and those obtained from nasopharyngeal and oropharyngeal swabs."

The greatest scientific advantage, said Dr. Brooks, is that nasal and oral swabs only collect the surface area where the swab goes, which may not be the place with most viral load. In contrast, the virus occurs throughout a saliva sample, so the test is more trustworthy.

The lab at Rutgers can process 20,000 tests a day, with a 48-hour turnaround. They have 75,000 tests ready to ship now.

The Leap: Detecting Sickness Before You Feel It

"We wanted to create a device that could detect infections before symptoms appeared," explained Nicholas Meyerson, co-founder and CEO of Darwin.

For more than 300 years, he said, "the thermometer was the gold standard for detecting disease because we thought the first sign of illness was a fever. This COVID-19 pandemic has proven that not all pathogens cause a fever. You can be highly contagious without knowing it."

"The question is whether we can scale up fast enough to meet the need. I believe saliva testing can help."

Therefore, Meyerson and co-founder Sara Sawyer from the University of Colorado began to identify RNA biomarkers that can sense when a pathogen first enters a molecule and "sets off alarms." They focused on the nucleic acids concentrated in saliva as the best and easiest place to collect samples for testing.

"The isothermal reaction in saliva takes place at body or room temperature," he said, "so there's no need for complicated testing machinery. The chemical reaction can be read out on a paper strip, like a pregnancy test -- two stripes if you're sick, and one stripe if you're okay."

Before the pandemic, limited but successful human trials were already underway at CU in Boulder and at the CU Anschutz Medical Campus east of Denver. "This was our proof of concept," he said.

Darwin was founded in March and has secured enough venture capital to concentrate protype development on detecting the virus causing COVID-19. So far, said Meyerson, "Everything works."

A small double-blind test of 30 samples at CU produced 100 percent accuracy. "I'm not sure if that will hold true as we go into clinical trials," he said, "but I'm confident we will satisfy all the requirements for at least 95 percent clinical validation."

The specific "CoVStick" test strips will roll out soon, he said: "We hope before the second wave of the pandemic hits."

The broader saliva test-strip product from Darwin, "SickStick," is still one to two years away from deployment by the military and introduction into the consumer drugstore market for home use, said Meyerson. It will affordably and quickly detect a range of viral and bacterial infections.

An illustration of the "CoVStick."

(Darwin Biosciences)

A Potential Game Changer

Society needs widespread testing daily, said George Church, founding core faculty of the Wyss Institute for Biologically Inspired Engineering at Harvard University. Speaking at an online SynBioBeta webinar in April, he urged developing stockpiles of testing kits for home use.

As for any potential of false positives, Church said a much bigger risk is not having enough tests.

"Saliva testing is going to speed up the timeline for opening society a lot," said Meyerson. "People need to self-collect samples at home. A lot more people are going to be willing to spit into a tube than to push a swab six inches up their own nose."

Brooks, of Rutgers, addressed the big picture. "It's critical that we open society as soon as possible to minimize the economic impact of the pandemic. Testing is the surest and safest path. The question is whether we can scale up fast enough to meet the need. I believe saliva testing can help."

Judah Freed
Judah Ken Freed is an award-winning author, seasoned journalist and book publishing consultant based in Denver. His two thousand published articles and essays have run in local and global publications from Westword to Huffington Post to The Sun. A futurist at heart, he pioneered coverage of the internet and interactive TV for the top media industry trade magazines in the USA and Europe (Multichannel News, TV Technology, Euromedia, Inter@ctive Week, others). His interviews with media visionaries, and his writings on the social effects of new media, drew calls to speak on four continents. His writings on global thinking, featured on BookTV, won 2007 and 2012 Nautilus Awards for best social change books. Inspired by being a Stage IV cancer survivor, and informed by his work as the Director of Publishing for RIP Medical Debt, he is keen to write about innovations in the life sciences for leapsmag. Follow him at JudahFreed.com or @judahfreed.

Immunity tests have too many unknowns right now to make them very useful in determining protective antibody status.

(© tilialucida and Grispb/Adobe)

[Editor's Note: We asked experts from different specialties to weigh in on a timely Big Question: "How should immunity testing play a role in re-opening society?" Below, a virologist offers her perspective.]

With the advent of serology testing and increased emphasis on "re-opening" America, public health officials have begun considering whether or not people who have recovered from COVID-19 can safely re-enter the workplace.
"Immunity certificates cannot certify what is not known."

Conventional wisdom holds that people who have developed antibodies in response to infection with SARS-CoV-2, the coronavirus that causes COVID-19, are likely to be immune to reinfection.

For most acute viral infections, this is generally true. However, SARS-CoV-2 is a new pathogen, and there are currently many unanswered questions about immunity. Can recovered patients be reinfected or transmit the virus? Does symptom severity determine how protective responses will be after recovery? How long will protection last? Understanding these basic features is essential to phased re-opening of the government and economy for people who have recovered from COVID-19.

One mechanism that has been considered is issuing "immunity certificates" to individuals with antibodies against SARS-CoV-2. These certificates would verify that individuals have already recovered from COVID-19, and thus have antibodies in their blood that will protect them against reinfection, enabling them to safely return to work and participate in society. Although this sounds reasonable in theory, there are many practical reasons why this is not a wise policy decision to ease off restrictive stay-home orders and distancing practices.

Too Many Scientific Unknowns

Serology tests measure antibodies in the serum—the liquid component of blood, which is where the antibodies are located. In this case, serology tests measure antibodies that specifically bind to SARS-CoV-2 virus particles. Usually when a person is infected with a virus, they develop antibodies that can "recognize" that virus, so the presence of SARS-CoV-2 antibodies indicates that a person has been previously exposed to the virus. Broad serology testing is critical to knowing how many people have been infected with SARS-CoV-2, since testing capacity for the virus itself has been so low.

Tests for the virus measure amounts of SARS-CoV-2 RNA—the virus's genetic material—directly, and thus will not detect the virus once a person has recovered. Thus, the majority of people who were not severely ill and did not require hospitalization, or did not have direct contact with a confirmed case, will not test positive for the virus weeks after they have recovered and can only determine if they had COVID-19 by testing for antibodies.

In most cases, for most pathogens, antibodies are also neutralizing, meaning they bind to the virus and render it incapable of infecting cells, and this protects against future infections. Immunity certificates are based on the assumption that people with antibodies specific for SARS-CoV-2 will be protected against reinfection. The problem is that we've only known that SARS-CoV-2 existed for a little over four months. Although studies so far indicate that most (but not all) patients with confirmed COVID-19 cases develop antibodies, we don't know the extent to which antibodies are protective against reinfection, or how long that protection will last. Immunity certificates cannot certify what is not known.

The limited data so far is encouraging with regard to protective immunity. Most of the patient sera tested for antibodies show reasonable titers of IgG, the type of antibodies most likely to be neutralizing. Furthermore, studies have shown that these IgG antibodies are capable of neutralizing surrogate viruses as well as infectious SARS-CoV-2 in laboratory tests. In addition, rhesus monkeys that were experimentally infected with SARS-CoV-2 and allowed to recover were protected from reinfection after a subsequent experimental challenge. These data tentatively suggest that most people are likely to develop neutralizing IgG, and protective immunity, after being infected by SARS-CoV-2.

However, not all COVID-19 patients do produce high levels of antibodies specific for SARS-CoV-2. A small number of patients in one study had no detectable neutralizing IgG. There have also been reports of patients in South Korea testing PCR positive after a prior negative test, indicating reinfection or reactivation. These cases may be explained by the sensitivity of the PCR test, and no data have been produced to indicate that these cases are genuine reinfection or recurrence of viral infection.

Complicating matters further, not all serology tests measure antibody titers. Some rapid serology tests are designed to be binary—the test can either detect antibodies or not, but does not give information about the amount of antibodies circulating. Based on our current knowledge, we cannot be certain that merely having any level of detectable antibodies alone guarantees protection from reinfection, or from a subclinical reinfection that might not cause a second case of COVID-19, but could still result in transmission to others. These unknowns remain problematic even with tests that accurately detect the presence of antibodies—which is not a given today, as many of the newly available tests are reportedly unreliable.

A Logistical and Ethical Quagmire

While most people are eager to cast off the isolation of physical distancing and resume their normal lives, mere desire to return to normality is not an indicator of whether those antibodies actually work, and no certificate can confer immune protection. Furthermore, immunity certificates could lead to some complicated logistical and ethical issues. If antibodies do not guarantee protective immunity, certifying that they do could give antibody-positive people a false sense of security, causing them to relax infection control practices such as distancing and hand hygiene.

"We should not, however, place our faith in assumptions and make return to normality contingent on an arbitrary and uninformative piece of paper."

Certificates could be forged, putting susceptible people at higher exposure risk. It's not clear who would issue them, what they would entitle the bearer to do or not do, or how certification would be verified or enforced. There are many ways in which such certificates could be used as a pretext to discriminate against people based on health status, in addition to disability, race, and socioeconomic status. Tracking people based on immune status raises further concerns about privacy and civil rights.

Rather than issuing documents confirming immune status, we should instead "re-open" society cautiously, with widespread virus and serology testing to accurately identify and isolate infected cases rapidly, with immediate contact tracing to safely quarantine and monitor those at exposure risk. Broad serosurveillance must be coupled with functional assays for neutralization activity to begin assessing how protective antibodies might actually be against SARS-CoV-2 infection. To understand how long immunity lasts, we should study antibodies, as well as the functional capabilities of other components of the larger immune system, such as T cells, in recovered COVID-19 patients over time.

We should not, however, place our faith in assumptions and make return to normality contingent on an arbitrary and uninformative piece of paper. Re-opening society, the government, and the economy depends not only on accurately determining how many people have antibodies to SARS-CoV-2, but on a deeper understanding of how those antibodies work to provide protection.

Angela Rasmussen
Dr. Angela Rasmussen uses systems biology techniques to interrogate the host response to viral infection. She has studied a huge range of viral pathogens, from the “common cold” (rhinovirus) to Ebola virus to highly pathogenic avian influenza virus to SARS-CoV-2/COVID-19. By combining current classical approaches to modeling infection and pathogenesis with sequencing technology and machine learning, Dr. Rasmussen and her colleagues and collaborators have identified new host mechanisms by which viruses cause disease.

Testing for immunity to COVID-19 will allow frontline health workers to safely go back to work, knowing they can't spread the disease.

(© chompoo/Adobe)

While testing for COVID-19 ramps up around the country, there's another kind of testing that will prove equally important to combating the pandemic: one that can detect whether someone has already been infected.

"The idea is that this assay can be established anywhere in the world following these steps."

Why is this important? As former FDA commissioner Scott Gottlieb wrote in today's Wall Street Journal: "If a sizable portion of a local community has some protection, authorities can be more confident in relying less on invasive measures. Once deployed, serological tests are cheap, straightforward, and easy to scale."

Now, a microbiology lab at the Icahn School of Medicine at Mount Sinai, led by Dr. Florian Krammer, has just announced the development of this serological test. Leapsmag spoke with Daniel Stadlbauer, a post-doctoral fellow in the lab who helped lead the work.

Is yours the first serological test available?

They did something similar in South Korea. In the U.S., it's the first of these tests.

How close are we to rolling this test out to the public?

Last week, we started this process and we finished the protocol today. Mount Sinai is trying to roll this out in the next few days in the clinic to see which patients have been infected with coronavirus recently or have been infected at all.

The protocol we uploaded today can be used as a template for other research labs or hospitals to follow the steps we provided and they should then be able to set up the antibody test. The idea is that this assay can be established anywhere in the world following these steps.

Are there any bottlenecks to getting this rolled out – supply chain or regulation obstacles?

There are no regulations that say you can't do it. Research labs and hospitals for sure can do it. I'm not aware of supply chain issues because you need basic lab equipment and materials, but I don't think those are in short supply right now.

How does the test work?

People coming to the hospital who are suspected to have infection with coronavirus, their blood gets taken routinely. This blood can be used for our test, too. The test will tell you if this person has antibodies against coronavirus. You can also test the blood of people who are not currently sick to see if this person was infected, say, a month ago. If there are antibodies in the blood, you can say this person is probably immune to getting it again.

It will be essential workers who need to be tested first, like nurses, firefighters, and doctors. It will be great to know that they would not put themselves or others at risk by going back to work because they cannot spread the disease.

"People probably cannot get reinfected once they mount a good immune response and have good antibody levels."

How soon after infection does the test detect if you have antibodies?

Usually after 7 days of infection.

How long do the antibodies last to confer immunity?

Those studies need to be done – right now it's unclear. People probably cannot get reinfected once they mount a good immune response and have good antibody levels. How long those level last still needs to be investigated. But they won't get reinfected in the next, I would say, six months.

How accurate is the test?

Very accurate. The advantage – which is bad for us but good for the test – is that humans have no baseline immunity to this coronavirus. It means that when you have not been infected, you have pretty much no antibodies, which is why it can spread so easily. But once you have antibodies in your blood, we can detect them and it's a clear difference between antibodies or no antibodies.

Where should hospitals and labs go for more information on how to build their own tests from your work?

They should check out our lab website to find the detailed protocol to download.

If I am a person who just wants to take this test to find out if I've already been infected, what should I do?

It will be done soon in the clinical setting. I don't know yet how widely it will be available. The more research labs and hospitals that set up this testing, the more people who can be tested in the future.

Kira Peikoff
Kira Peikoff is the editor-in-chief of Leaps.org. As a journalist, her work has appeared in The New York Times, Newsweek, Nautilus, Popular Mechanics, The New York Academy of Sciences, and other outlets. She is also the author of four suspense novels that explore controversial issues arising from scientific innovation: Living Proof, No Time to Die, Die Again Tomorrow, and Mother Knows Best. Peikoff holds a B.A. in Journalism from New York University and an M.S. in Bioethics from Columbia University. She lives in New Jersey with her husband and son.