BD Exec: Antigen Tests Are Reliable on COVID-19, But Community Spread Plays Role in False Results

The federal government’s push to send out rapid point-of-care antigen test for COVID-19 to all nursing homes officially wrapped in the early months of autumn. But for many skilled nursing facilities, the use of the tests was fraught, with questions lingering about accuracy and refills of supplies.

Those concerns began to ease as fall wore on, with supplies in particular improving with time, but with COVID-19 surging again heading into the winter months, rapid test results for SNFs remain paramount.

Becton Dickinson’s Veritor is the device primarily being used in the push by the Department of Health and Human Services (HHS) to provide rapid tests to SNFs, which was announced in July — after the Veritor was granted an emergency use authorization (EUA) by the Food and Drug Administration (FDA).

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Dr. Jeffrey Andrews, worldwide medical director for molecular diagnostics at BD Integrated Diagnostics solutions, sat down with Skilled Nursing News in November to discuss the Veritor, BD’s work with HHS, and the supply refills for nursing homes that are making use of the tests.

This interview was recorded on November 19 and reflects the COVID-19 situation of that time; it has been condensed and edited for clarity.

The BD Veritor’s results were established “with 226 direct nasal swabs prospectively collected and enrolled from individual symptomatic patients,” according to the instructions for use. Have there been any studies of how the Veritor performed on samples taken from asymptomatic individuals? If not, are there any plans to conduct such a study?

That’s a great question. You’re correct, our test is currently authorized for use on individuals suspected of COVID-19 by their health care provider, within the first five days of onset of symptoms for symptomatic [individuals]. And in accordance with statements that the FDA has issued, for instance, on August 14, our test can also be used on asymptomatic individuals suspected of having COVID-19 by their health care providers, such as because of a known exposure to an infected individual, or [because] they live or work in a high-risk congregate setting environment.

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For the skilled nursing facilities, we were clear in our discussions with HHS that our instructions and intended use of a test for CLIA-waived facilities is to test symptomatic patients within five days of onset. Ultimately, how HHS and the states and the nursing homes and the skilled nursing facilities use the test is up to the discretion of the medical director who’s overseeing the testing program and the CLIA lab certificate of waiver.

Of course, we have a whole training system and YouTube videos for the workflow and guidance on scenarios for when the test can be used, and we also have a customer service hotline.

The data that we collected in our clinical study have been specific to symptomatic patients. So we currently don’t have published data to support any performance claims for asymptomatic patients.

[For plans to test in asymptomatic populations], I’ll say that BD is a scientific company. Medical Affairs, that I work in, is constantly up-to-the minute tracking what’s happening with the science, with the use of tests and needs for tests. We get continuous feedback from our customers, and we’re constantly developing and responding to those needs. And I can’t get more specific with you, for reasons that you can imagine.

What are the situations, then, in which the Veritor best deployed — a situation where COVID is fairly widespread in the community? Or for more general screening purposes?

Your instinct is right: The higher the new daily cases in the community, the more important testing becomes. And this is the situation across the U.S.A. today [November 19] as as we speak, we’re seeing high daily case rates.

Again, our test is authorized for use on most individuals suspected of COVID-19 and also can be used, according to the FDA and CDC [Centers for Disease Control and Prevention], on asymptomatic individuals with a known history of exposure or people living or working in a congregate setting. And certainly nursing homes, skilled nursing facilities, residents and staff are included under those directives from HHS, FDA, and CDC.

So we’re supporting the use of the tests in all the nursing homes, and we’ve delivered ours to more than 70% of the total nursing homes. That’s supporting those vulnerable patients and the critical staff who work in those facilities. So far, we’ve delivered more than 11,000 of the analyzers and more than 3.75 million of the test kits to support testing in the more than 15,000 nursing homes across the U.S. And that shipping was done directly to the nursing homes under the direction of HHS.

When you say the shipping is done under the direction of HHS, what is the involvement of HHS in that shipping of it?

Typically, BD can work directly with customers, but we often work with distributors, just as part of the efficient way that health care products get delivered. In this particular case, Admiral Giroir, the assistant secretary of health, used the Defense Production Act (DPA) to ask BD to deliver the Veritor analyzers and test strips to the nursing homes. That was a direct delivery of products. As soon as we completed that, we made it possible for all the nursing homes to replenish their supplies of test kits through our distributors.

For those test kits refills, how quickly are they being shipped out right now, in terms of being replenished? Back in July, the prediction was that the supplies would be fully up and running by fall, so I wanted to check on that — are they fully online?

Yes, they are. We fulfilled that initial commitment under the DPA in early September. We made sure that all of our distributors knew what was going on, and in particular that the administration has prioritized nursing homes and SNFs, as well as prioritizing what the government calls “red areas” — where there’s a high community prevalence. So we’re making sure that those orders are prioritized above other orders.

And our distributors are getting a continuous supply of tests to sell to all the customers, but prioritized to the nursing homes and skilled nursing facilities.

Do you have a sense of many test kits are going out to distributors right now?

I think it’s about 8 million a month production right now, trending upward to 12 million by March [2021].

Are there any common questions from nursing homes about making use of the Veritor — questions about the best population to use the test with, or something similar?

Who to test, how often to test, those sorts of things come from the CDC; the CDC issued a document — let’s call it an algorithm, or a decision tree — that outlines, depending on whether there’s been an outbreak recently or not, the recommendations for how who to test and how often to test. And then it also goes through how the nursing home medical director should respond to positive and negative results.

We of course just recommend that people follow the CDC directions, which were written specifically for the HHS outreach to nursing homes.

In terms of the type of questions that BD receives, they’re usually the same ones that we’ve addressed in our FAQs, because that’s how we develop them — and then just questions that are covered by our online training modules and, and videos. So we have a variety of tools to help educate all the teams on the use of the BD Veritor test and the analyzer. We’ve provided education upfront.

Of course, there’s written instructions for use in every test package, but at our special dedicated website, there’s a whole training program, instructional videos, and there’s also 10 videos on YouTube that go through all the different applications of the test.

We also have five webinars that we’ve done that we saved, that can be watched on demand. We have a call center [where] you can have an immediate chat or you can put in a request for a call back.

There’s been, as you’ve probably seen, different press reports on questions about the false positives and false negatives for the Veritor and how that ties into prevalence rates of COVID-19 in the community. Can you explain when you’re more likely to have false positives and negatives, and some of the specifics of those findings?

If you picture a box with four parts in it, those are the four types of results: true positive, false positive, true negative, false negative. Any of those are possible with any test. Most importantly, the BD Veritor rapidly detects the true positive cases — and that’s the purpose of testing, because when you can rapidly identify those folks, they can be isolated and prevent the spread of COVID-19.

No test is perfect; there will will naturally always be some number of false positives. In this case, the false positive rate with the BD Veritor antigen test is incredibly low, but that low number becomes a concern in a low-prevalence setting. However, in low-prevalence settings, that means you’re only getting very few positive results out of the thousand people that you’re testing. Therefore, it’s practical to retest those individuals, which you’ll see in that CDC guidance.

The FDA expects SARS-CoV-2 point-of-care tests to demonstrate a negative percent agreement, also known in statistics as specificity, that should be 95% or better. The specificity in our package insert is 100%, with a confidence interval of 98% to 100%. That means that the BD clinical studies performed at more than 20 sites demonstrated a false positive rate averaging about 0.5% and less than 2% of all tests performed.

Simply put, in a low-prevalence setting, that means if you use the BD Veritor, you might see zero to two false positives for every 100 tests that you conduct. That’s for a low prevalence setting. That’s excellent accuracy. It’s in line with similar tests for flu A and B, for strep A and RSV [respiratory syncytial virus], also on the BD Veritor system, all of which have been widely used for years and are highly relevant and clinically valid.

Now, a negative result is also reliable as a true negative — except when the person is symptomatic, consistent with COVID-19. In that case, the FDA and the CDC recommend repeating any rapid test that’s negative in a highly symptomatic patient because of the possibility that it’s a false negative. In that case, the patient is quarantined, pending the result of the definitive test, which is the molecular test, also known as the PCR [polymerase chain reaction] test.

This is well understood by FDA and HHS: that there will be a small number of false positives, a small number of false negatives, and the clinical interpretation directive from the CDC covers all of that appropriately.

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