Clinical laboratories could play a key role in helping users collect their samples correctly, interpret results, and transfer flu test data to their health records
Clinical laboratories may have another opportunity to provide service to their clients and the physicians who treat them. With the success of at-home COVID-19 testing, consumer demand for self-tests is changing and advances in diagnostic technology now make it feasible to make more influenza (flu) tests available for consumers to buy and use at home.
At-home tests for SARS-CoV-2 can be found at pharmacies all across America. But that’s not the case with tests for influenza.
Should self-test flu kits eventually become available and common, clinical laboratories could offer the service of helping consumers understand:
that the test was conducted correctly (specimen collection and analysis),
“Home flu testing would ensure that those who do need and receive antiviral medication for influenza are the ones who need it the most,” and that “we are making our treatment decisions based on data,” infectious disease specialist Christina Yen, MD (above), University of Texas Southwestern Medical Center, told STAT News. At-home flu self-tests could also bring opportunities for clinical laboratories to provide service to healthcare consumers and the physicians who treat them. (Photo copyright: UT Southwestern Medical Center.)
Pros and Cons of Consumers Doing At-home Influenza Testing
According to the federal Centers for Disease Control and Prevention (CDC), COVID-19 and influenza are both upper respiratory illnesses with similar symptoms. So, why don’t we have more at-home flu tests available? Partly because at-home testing is a relatively new phenomenon in modern healthcare.
“It’s really rare, and it’s really new that people are allowed to know about what’s happening inside their body without a physician in the middle,” Harvard epidemiologist Michael Mina, MD, PhD, told STAT News. The article uses the example of at-home pregnancy tests. Despite a prototype for an at-home pregnancy test being created in 1967, it took another decade before an over-the-counter pregnancy test became available to the public.
“The general thinking was, ‘How could a woman possibly know what to do if she found out she was pregnant on her own without a doctor in the room?’ That is a ridiculous concern because women have been doing that for millions of years,” Mina added.
So, why be cautious when it comes to giving patients the option of at-home flu testing?
There are some cons to at-home influenza tests. Average citizens are not clinical laboratory professionals. They might obtain too little sample for an accurate reading or read the results incorrectly. Then, there is the possibility for false-negatives or false-positives.
An at-home test user is not likely to consider the possibility of a false result, however clinicians look at the situation with more nuance. If the patient was still symptomatic or in a high-risk community, the provider could administer a more sensitive medical laboratory test to confirm the previous test results.
“In a Facebook post from mid-November with hundreds of responses, concertgoers compared symptoms and positive test results, many of those from tests taken at home. But those data weren’t added to state public health tallies of COVID’s spread,” STAT News noted.
The larger concern is that samples obtained by at-home self-test users are not submitted for genomic sequencing. This could lead to incomplete data and delay identifying new variants of the coronavirus in communities.
Another barrier to at-home flu testing is that rapid influenza diagnostic testing can be unreliable. In 2009, the rapid influenza tests could only detect the H1N1 influenza virus in a mere 11% of samples, STAT News reported. Because of this, the FDA now requires manufacturers to test their rapid tests against eight different strains that change every year depending upon which strains are prevalent. This could present a problem if individuals use leftover tests from the previous flu season.
Do Pros of At-home Testing Outweigh the Cons?
At-home testing is convenient and makes testing more accessible to patients who may not be able to get to a clinic. Being able to test at home also encourages individuals to take precautions necessary to stop the spread of whichever illness they may have. Given the similarities in symptoms between influenza and COVID-19, people could benefit from having tools at home that correctly identify their illness.
At-home COVID-19 tests are here to stay, and at-home influenza tests may be on the way soon. Clinical laboratories could play an important role in educating the public on the correct handling of these tests.
Developers of medical laboratory tests had high hopes that cheap saliva-based tests would compete with at-home OTC tests that use nasal swabs, but skepticism among scientists continues
Reverse-transcription polymerase chain reaction (RT-PCR) technology has become the standard for clinical laboratory diagnostic testing used to detect the presence of the SARS-CoV-2 coronavirus. However, to enable more widespread testing, some public health experts have called for deployment of cheap, rapid, saliva-based antigen tests that could be self-administered by consumers in their homes.
Despite the technology’s lower sensitivity compared with RT-PCR testing, the idea of “fast-and-frequent” universal antigen testing has gained support as a possible game-changer against the outbreak, the New York Times reported.
The FDA recently took a step in this direction with its first emergency use authorization for the Ellume COVID-19 at-home antigen test. But other developments suggest that these tests may fall short of the lofty vision initially outlined by the experts.
Ellume’s COVID-19 Home Test (above) received emergency use authorization from the FDA on December 15. In a press release, Ellume claimed its rapid-antigen test, “demonstrated a sensitivity of 96% and specificity of 100%, and in asymptomatic individuals, the test demonstrated a sensitivity of 91% and specificity of 96%. This level of accuracy across both symptomatic and asymptomatic individuals is crucial in mitigating the spread of an infectious disease like COVID-19.” (Photo copyright: Ellume.)
The Promise of Rapid Antigen COVID-19 Tests
In a column he wrote for Time in July, Ashish K. Jha, MD, MPH, a practicing General Internist and Dean of the Brown University School of Public Health, described the promise of rapid antigen tests. “Imagine spitting on a special strip of paper every morning and being told two minutes later whether you were positive for COVID-19,” he wrote. “If everyone in the United States did this daily, we would dramatically drop our transmission rates and bring the pandemic under control.”
Another advocate for this approach is Michael Mina, MD, PhD, an assistant professor of epidemiology at the Harvard T.H. Chan School of Public Health and a core member of the School’s Center for Communicable Disease Dynamics (CCDD). In a commentary for Time in November he wrote, “Widespread and frequent rapid antigen testing (public health screening to suppress outbreaks) is the best possible tool we have at our disposal today—and we are not using it.”
However, one major issue with antigen testing is sensitivity. “Antigen tests require higher levels of virus than qPCR [quantitative polymerase chain reaction] to return a positive result,” Jha wrote in Time. However, he contends, “the frequency of testing and the speed of results” counter concerns about accuracy.
Even with lower sensitivity, Jha wrote, the quicker test results from antigen tests “would identify viral loads during the most infectious period, meaning those cases we care most about identifying—at the peak period of infectiousness—are less likely to be missed.”
As the FDA explains, RT-PCR molecular tests “detect the virus’ genetic material,” whereas, according to an article published in Nature, titled, “Fast Coronavirus Tests: What They Can and Can’t Do,” antigen tests can “detect specific proteins … on the surface of the virus, and can identify people who are at the peak of infection, when virus levels in the body are likely to be high.”
At-Home Antigen Tests Receive EUAs
The new antigen test developed by Ellume is “the first over-the-counter (OTC) fully at-home diagnostic test for COVID-19,” the FDA said in a press release. The user self-administers a nasal swab and places it in an analyzer connected to a smartphone app. It can deliver results in 20 minutes. The company states that its test has overall sensitivity of 95% and specificity of 97% based on a clinical study of 198 subjects in a simulated home setting.
Jeffrey Shuren, MD, JD, Director of FDA’s Center for Devices and Radiological Health, said in the FDA press release, “This test, like other antigen tests, is less sensitive and less specific than typical molecular tests run in a lab. However, the fact that it can be used completely at home and return results quickly means that it can play an important role in response to the pandemic.”
Ellume expects to deliver about 20 million tests to the US by the end of June 2021. Multiple outlets reported that the test will cost about $30, AP News reported.
Meanwhile, the FDA also authorized at-home use of Abbott’s BinaxNOW rapid antigen test, which was previously authorized for use in point-of-care settings. This test, which requires a prescription, will sell for $25.
In a series of tweets, Harvard’s Mina applauded both moves, but he wrote that they [antigen tests] still fall short of his vision for fast and frequent testing. He described Abbott’s BinaxNOW as “the type of rapid test I have been calling for,” but said he’d like to see tests priced far less and available without a prescription.
Diminishing Prospects for Saliva-based Antigen Tests?
All rapid antigen tests authorized by the FDA so far require nasopharyngeal and/or nasal swab specimens, and it appears that it may be a long time, if ever, before saliva-based antigen tests are available. The New York Times (NYT) reported in October that two companies working on antigen tests—E25Bio and OraSure (NASDAQ:OSUR)—have dropped plans to enable use of saliva.
“If I was placing a bet—which I am, because I’m leading an antigen-based testing company—I would say it’s going to be very difficult for antigen-based testing to work on saliva samples,” E25Bio founder Bobby Brooke Herrera, PhD (above with E25Bio co-founder and Chief Technology Officer Irene Bosch) told the NYT. (Photo copyright: WCVB-TV.)
One advantage of a saliva-based test is that it would be easier to self-administer. “But as they continued to tinker with their tests, researchers at both E25Bio and OraSure found saliva’s performance to be more lackluster than anticipated, and were forced to pivot,” the New York Times reported. Instead, both companies will seek authorization for use of their tests with nasal swabs.
HHS Contract for Antigen Tests Brings High Rates of False Positives
A recent investigative story in ProPublica, titled, “Rapid Testing Is Less Accurate than the Government Wants to Admit,” raised additional questions about rapid antigen testing. In August, the US Department of Health and Human Services announced it had awarded a $760 million contract for 150 million Abbott BinaxNOW tests to be distributed to schools and nursing homes. But later, according to ProPublica, healthcare workers in Nevada and Vermont reported high rates of false positives.
“With the benefit of hindsight, experts said the Trump administration should have released antigen tests primarily to communities with outbreaks instead of expecting them to work just as well in large groups of asymptomatic people,” ProPublica reported. “Understanding they can produce false results; the government could have ensured that clinics had enough for repeat testing to reduce false negatives and access to more precise PCR tests to weed out false positives.”
A few weeks after the reports from Nevada and Vermont, the FDA issued a letter advising clinical laboratories and healthcare providers about the possibility of false positives, along with steps they could take to improve accuracy.
Though some experts remain hopeful about “fast-and-frequent” testing, others are skeptical and say more research is needed to assess the value of this approach. “We are open to thinking outside the box and coming up with new ways to handle this pandemic,” Esther Babady PhD, D(ABMM) of Memorial Sloan Kettering Cancer Center, told the New York Times. However, she added, “the data for that is what’s missing.”
Nevertheless, were at-home rapid saliva-based antigen tests to become a common choice for healthcare consumers, clinical laboratories that perform RT-PCR testing for COVID-19 could see a marked decrease in orders. Thus, regardless of the current state of antigen testing, its development is worth watching.
Abbott sends the SARS-CoV-2 test results directly to patients’ smartphones, which can be displayed to gain entrance into areas requiring proof of COVID-19 testing
There is no greater example that COVID-19 is a major force for change in the clinical laboratory industry than the fact that—though the US federal government pays 50% of the nation’s total annual healthcare spend of $3.5 trillion—it recently spent $760 million to purchase 150 million COVID-19 tests from Abbott Laboratories (NYSE:ABT), an American multinational medical devices and healthcare company headquartered in Abbott Park, Ill., “to expand strategic, evidence-based testing in the United States,” according to the company’s website.
In August, the federal Food and Drug Administration (FDA) granted an emergency use authorization (EUA) to Abbott for its BinaxNOW portable rapid-response COVID-19 antigen (Ag) test. The credit-card sized test costs $5 and can return clinical laboratory test results in minutes, rather than hours, days, or in some cases, weeks, the Wall Street Journal (WSJ) reported.
The test includes a free smartphone app called NAVICA, which enables those tested to receive their test results directly on their mobile devices—bypassing the patient’s primary care physicians.
According to Abbott’s website, the app “allows people who test negative to get an encrypted temporary digital NAVICA Pass, similar to an airline boarding pass. NAVICA-enabled organizations will be able to verify an individual’s negative COVID-19 test results by scanning the individual’s digital NAVICA Pass to facilitate entry into facilities.”
This feature of Abbott’s new COVID-19 test is a good example of how quickly innovation in the medical laboratory testing profession is bringing new features and new capabilities to the marketplace. By marrying the SARS-CoV-2 test with the NAVICA Pass feature, Abbott hopes to deliver increased value—not just to physicians and their patients—but also to employers with employee screening programs and federal government programs designed to screen federal employees, as well as being used for screening travelers at airports and other transportation hubs.
Abbott appears to be banking that in the future such identification will be required to “enter organizations and other places where people gather,” as the company’s website states.
Testing Limited to CLIA-Certified Clinical Laboratories
An HHS news release announcing the government’s planned distribution of the BinaxNOW tests stated that “Testing will be potentially deployed to schools and to assist with serving other special needs populations.”
In the news release, Alex Azar, HHS Secretary, said, “By strategically distributing 150 million of these tests to where they’re needed most, we can track the virus like never before and protect millions of Americans at risk in especially vulnerable situations.”
The EUA adds that “Testing of nasal swab specimens using [BinaxNOW] … is limited to laboratories certified under CLIA that meet the requirements to perform high, moderate, or waived complexity tests. This test is authorized for use at the [point of care], i.e., in patient care settings operating under a CLIA Certificate of Waiver, Certificate of Compliance, or Certificate of Accreditation.”
The FDA’s EUA describes the BinaxNOW portable rapid-response COVID-19 antigen test (above) as “a lateral flow immunoassay intended for the qualitative detection of nucleocapsid protein antigen from SARS-CoV-2 in direct nasal swabs from individuals suspected of COVID-19 by their healthcare provider within the first seven days of symptom onset.” The test costs $5 and Abbott sends results directly to the patient’s smartphone using the free NAVICA app included with the test. (Photo copyright: Abbott Laboratories.)
IVD Companies See Boom in COVID-19 Test Sales
Demand for COVID-19 testing has created opportunities for in vitro diagnostics (IVD) companies that can develop and bring tests to market quickly.
Recent issues of Dark Daily’s sister print publication—The Dark Report (TDR)—covered IVD companies’ second quarter (Q2) boom in sales of COVID-19 instruments and tests, while also noting a fall-off in routine clinical laboratory testing during the COVID-19 pandemic.
Abbott Laboratories saw molecular diagnostics sales increase 241% in Q2 driven by $283 million in sales of COVID-19 testing, while rapid diagnostic COVID-19 testing rose 11% on $180 million in sales in Q2, TDR reported, based on Abbott data.
“There is huge economic incentive for diagnostic companies to develop technologies that can be used to create rapid tests that are cheap to perform,” said Robert Michel, Publisher and Editor-in-Chief of TDR and Dark Daily. “In this sense, COVID is a major force for change.”
“This new COVID-19 antigen test is an important addition to available tests because the results can be read in minutes, right off the testing card,” said Jeff Shuren, MD, JD (above), Director of the FDA’s Center for Devices and Radiological Health (CDRH), in an FDA news release announcing the federal government’s $760 million purchase of 150 million Abbott BinaxNOW rapid-response antigen COVID-19 tests. “This means people will know if they have the virus in almost real-time. Due to its simpler design and the large number of tests the company anticipates making in the coming months, this new antigen test is an important advancement in our fight against the pandemic.” (Photo copyright: The New York Times.)
Thus, Abbott is determined to ensure this product launch is successful and that the test works as promised. According to a news release, “In data submitted to the FDA from a clinical study conducted by Abbott with several leading US research universities, the BinaxNOW COVID-19 Ag Card demonstrated sensitivity of 97.1% (positive percent agreement) and specificity of 98.5% (negative percent agreement) in patients suspected of COVID-19 by their healthcare provider within the first seven days of symptom onset.”
“The massive scale of this test and app will allow tens of millions of people to have access to rapid and reliable testing,” said Joseph Petrosino, PhD, professor and chairman, Molecular Virology and Microbiology, Baylor College of Medicine, in the Abbott news release. “With lab-based tests, you get excellent sensitivity but might have to wait days or longer to get the results. With a rapid antigen test, you get a result right away, getting infectious people off the streets and into quarantine so they don’t spread the virus.”
Abbott has invested hundreds of millions of dollars in two manufacturing facilities where the tests will be made, John Hackett Jr, PhD, an immunologist and Abbott’s Divisional Vice President Applied Research and Technology, and lead scientist on the BinaxNOW project, told The Atlantic.
“Our nation’s frontline healthcare workers and clinical laboratory personnel have been under siege since the onset of this pandemic,” said Charles Chiu, MD, PhD, professor of Laboratory Medicine at University of California, San Francisco, in the Abbott news release. “The availability of rapid testing for COVID-19 will help support overburdened laboratories, accelerate turnaround times, and greatly expand access to people who need it.”
However, other experts are not so sure. In the Atlantic article, Michael Mina MD, PhD, Assistant Professor Epidemiology at Harvard’s T.H. Chan School of Public Health, voiced the need to test both asymptomatic and pre-symptomatic people. “This is the type of [COVID-19] test we have been waiting for—but may not be the test.”
Nevertheless, the federal government’s investment is significant. Abbott plans to start shipping tens of millions of tests in September and produce 50 million tests per month starting in October, Forbes reported.
Shifting Clinical Laboratory Paradigms
BinaxNOW will be performed without doctors’ orders, in a variety of locations, and results go directly to patients’ smartphone—without a pathologist’s interpretation and medical laboratory report. This is new ground and the impact on non-CLIA labs, and on healthcare in general, is yet to be seen.
Clinical laboratory managers will want to monitor the rise of rapid-response tests that can be easily accessed, conducted, and reported on without physician input.
Though some experts claim widespread antibody testing is key to effective public health safety, the WHO warns positive serological tests may not indicate immunity from reinfection or transmission of SARS-CoV-2
It may be the largest program of clinical laboratory testing ever conducted in the United States. Health officials are preparing to undertake large-scale serological surveys (serosurveys) to detect and track previously undetected cases of SARS-CoV-2, the novel coronavirus, that causes the COVID-19 illness.
Microbiologists, epidemiologists, and medical laboratory leaders will be interested in these studies, which are aimed at determining how many adults in the US with no confirmed history of SARS-CoV-2 infection actually possess antibodies to the coronavirus.
Serological screening testing may also enable employers to identify employees who can safely return to their job. And researchers may be able to identify communities and populations that have been most affected by the virus.
Serological Study of COVID-19 Taking Place in Five States
In an interview with Science, Michael Busch, MD, PhD, Senior Vice President, Research and Scientific Affairs of Vitalant (formerly Blood Systems), one of the nation’s oldest and largest nonprofit community blood service providers, and Director of the Vitalant Research Institute, discussed several serological studies in which he is involved. The first study, which he said is being funded by the National Institutes of Health (NIH), is taking place in six metropolitan regions in the US: Seattle, New York City, San Francisco, Los Angeles, Boston, and Minneapolis.
The interesting twist in these studies is that they will test blood samples from people donating blood. In March, participating blood centers in each region started saving 1,000 donor samples per month. Six thousand samples will be assessed monthly for a six-month period using an antibody testing algorithm that enables researchers to monitor how people develop SARS-CoV-2 antibodies over time.
Busch told Science this regional study will evolve into three “national, fully representative serosurveys of the US population using blood donors.” This particular national serosurvey will study 50,000 donations in September and December of 2020 and in November 2021.
“We’re going to be estimating overall antibody prevalence to SARS-CoV-2 within each state, but also map it down within the states to regions and metropolitan urban areas, and look at the differences,” Busch told Science, which called the serosurvey “unprecedented.”
“It’s certainly the largest serosurvey I’ve ever been involved with,” Busch said.
In the third NIH serosurvey, according to Busch, NIH blood-donor serosurveys will be compared with results from population serosurveys taking place through the University of Washington and University of California San Francisco, which involve neighborhood door knocking and sampling from hematology labs.
“An antibody test is looking back into the immune system’s history with a rearview mirror,” said Matthew J. Memoli, MD (above,) an infection disease specialist with the NIH and Director of the National Institute of Allergy and Infectious Diseases (NIAID), in a news release. “By analyzing an individual’s blood, we can determine if that person has encountered SARS-CoV-2 previously.” (Photo copyright: National Institutes of Health.)
Some of the SARS-CoV-2 serological surveys underway include:
The National Institutes of Health serosurvey involving as many as 10,000 adults in the US who have no confirmed history of infection with SARS-CoV-2, which will analyze blood samples for two types of antibodies—anti-SARS-CoV-2 protein IgG and IgM. Researchers also may perform additional tests to evaluate volunteers’ immune responses to the virus.
A World Health Organization (WHO) coordinated follow-up study to its Solidarity Trial named Solidarity 2, which will “pool data from research groups in different countries to compare rates of infection,” which WHO officials say is ‘critical’ to understanding the true extent of the pandemic and to inform policy, Research Professionals News reported.
In Germany, the Robert Koch Institute, the country’s disease control and prevention agency, is tackling Europe’s first large-scale COVID-19 antibody testing. Its three-phase study will include serological testing on blood from donation centers, followed by testing on blood samples from coronavirus regional hotspots and then the country’s broader population.
But Can Serological Testing Prove Immunity to COVID-19?
However, whether having COVID-19 antibodies will make people immune to reinfection or unable to spread the disease is not yet known.
“We don’t have nearly the immunological or biological data at this point to say that if someone has a strong enough immune response that they are protected from symptoms, … that they cannot be transmitters,” Michael Mina, MD, PhD, Assistant Professor of Epidemiology at Harvard’s T.H. Chan School of Public Health and Associate Medical Director in Clinical Microbiology (molecular diagnostics) in the Department of Pathology at Brigham and Women’s Hospital, told STAT.
The Times of Sweden reported the WHO warned in mid-April that there is no proof recovering from COVID-19 provides immunity.
“There are a lot of countries that are suggesting using rapid diagnostic serological tests to be able to capture what they think will be a measure of immunity,” said Maria Van Kerkhove, PhD, the WHO’s Technical Lead for COVID-19, at a news conference in Geneva, Switzerland, the Times of Sweden reported.
“Right now, we have no evidence that the use of a serological test can show that an individual has immunity or is protected from reinfection,” she said, adding, “These antibody tests will be able to measure that level of seroprevalence—that level of antibodies—but that does not mean that somebody with antibodies [is] immune.”
In addition, the reliability and quality of some serological tests produced in China, as well as some being manufactured in the US, have come into question, the Financial Times reported.
Nevertheless, as serological testing for COVID-19 becomes more widespread, clinical laboratories should plan to play an ever-increasing role in the battle to stop a second wave of the epidemic in this country.
