FDA Virtual Townhall

Moderator: Irene Aihie

03-24-21/12:15 pm ET

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FDA Virtual Town Hall Series –

Immediately in Effect Guidance on 

Coronavirus (COVID-19) Diagnostic Tests

Moderator: Irene Aihie

March 24, 2021

12:15 pm ET

Coordinator: Welcome and thank you for standing by. At this time all participants are in a 

listen-only mode. At the end of today’s presentation we will conduct a 

question-and-answer session. To ask a question, please press star 1. Today’s 

conference is being recorded. If you have any objections you may disconnect 

at this time. I would now like to turn the meeting over to Irene Aihie. You 

may begin.

Irene Aihie: Thank you. Hello. I’m Irene Aihie of CDRH’s Office of Communication and 

Education. Welcome to the FDA’s 48th in a series of virtual town hall 

meetings to help answer technical questions about the development and 

validation of tests for SARS-CoV-2 during the public health emergency.

Today, Toby Lowe, Associate Director of the Office of In Vitro Diagnostics 

in Radiological Health and Timothy Stenzel, Director of the Office of In Vitro 
FDA Virtual Townhall

Moderator: Irene Aihie

03-24-21/12:15 pm ET

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Diagnostics in Radiological Health in the Office of Product Evaluation and 

Quality, both from CDRH will provide a brief update.

Following opening remarks, we will open the line for questions related to the 

development and validation of tests for SARS-CoV-2. Please remember, 

during this town hall we are not able to respond to questions about specific 

submissions that might be under review. Now, I give you Toby.

Toby Lowe: Thanks, Irene. Thanks everyone for joining us again. As we started, we 

mentioned last week, we started taking questions ahead of time by email so I 

will give an update on those as well as a follow up on a question or two from 

last week.

So first I want to touch on a question that came in during the call last week 

that we then followed up with over some emails and wanted to clarify for 

everyone on the call. This is regarding the use of pooling and in what 

situations that is considered screening versus surveillance.

We have gotten a number of questions about surveillance versus screening 

and it is a tricky topic.

So we did clarify with this specific situation that was asking about collecting a 

ten-swab pool where all the swabs are placed into the same transport tube with 

media. With the assumption that you plan to recollect specimens from each of 

those individuals if the pool is positive, where the intent is to determine each 

individual’s COVID-19 status for SARS-CoV-2 positive or negative status --

such that that individual could or would take action based on that result.

So in that case the testing protocol that was proposed appears to be screening 

since it is intended for individual action.
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Along those same lines we received over email one other question related to 

use of an EUA to test for surveillance purposes. And what I would like to ask 

is that anyone who is interested in or has specific questions about surveillance, 

please send those in by email.

We receive a lot of questions about testing proposals that are actually 

screening, not surveillance. And so we want to make sure that we have all the 

pertinent details before we give you feedback so that we can make sure that 

we provide the appropriate feedback for your specific situation.

So let me start walking through the rest of the questions here that we received. 

We received some questions about supporting a screening claim when there is 

already an EUA for the qualitative detection of SARS-CoV-2 and this is 

related to the supplemental EUA template that was issued last week.

So our recommendation generally for validating asymptomatic screening are 

included in the main molecular EUA template if you are interested in an 

individual screening claim.

If you are interested in the serial screening claim as outlined in the 

supplemental EUA template, you likely don’t need any additional 

preauthorization data. In that case we recommend that you submit a 

supplemental EUA request with your requested indication including the serial 

testing interval and your proposed post authorization validation study.

Regarding serial testing we also received a question about antigen tests and 

whether the serial testing approach would be acceptable if the antigen assay

does not reach the 80% sensitivity in symptomatic individuals.
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We do discuss in the antigen template for test developers that strategies for 

serial testing with less sensitive tests such as the PPO less than 80% may be 

able to support authorization. But in those cases we would expect the clinical 

evaluation in an asymptomatic population to be completed prior to 

authorization of a screening claim.

The shift of the validation to post authorization discussed in the supplemental 

template is not applicable for tests with sensitivity below 80% in symptomatic 

subjects.

Timothy Stenzel: And I would just add that the pathway for, you know, those suspected with 

COVID for an antigen test, you know, it’s still available for those that have a 

single test PPA of less than 80% and if, you want to use serial testing in the 

symptomatic population as well. So pathway still remains open as described in 

the health piece we wrote back in September. Thanks Toby.

Toby Lowe: Great. Thanks for adding that Tim. Next we received a question about the 

process for submitting data to OIR for an EUA, so to clarify, we do have the 

EUA templates for serology, antigen and molecular test up on our Web site 

and ask that you submit your EUA request to cdrh-euatemplates@fda.hhs.gov . Those templates generally reflect our current 

thinking on the data and information that developers should submit to 

facilitate the EUA review process.

Once we receive that we review your EUA request and determine whether it is 

sufficient to support an EUA authorization. And then at that point if we do 

believe it’s sufficient, we would authorize the test then issue the sponsor letter 

of authorization and add that test to the FDA landing page.
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Now we received a question about an OTC antigen test and asking to confirm 

that the data should show a minimum of 80% agreement with a predicate to be 

considered for approval for an EUA.

So just to clarify some terminology there, for an EUA review, it is different 

than a 510k review. So for an EUA, it is not a substantial equivalence 

determination so there is no predicate.

But we do often, you know, ask for a comparator test to be used in your 

clinical evaluation so I think that’s likely what this question is referring to.

And we do recommend for OTC tests in the antigen the - sorry, the non-lab 

template, we do recommend a minimum of 90% PPA for OTC tests as 

compared to the comparator test.

And in the new supplemental template issued last week we recommend a 

minimum of 80% PPA for serial testing claims.

Timothy Stenzel: And those PPAs are in symptomatic individuals. And the comparator test can 

be, you know, the recently granted molecular test and any subsequent ones

coming in for full authorization could use that test. But then if you use the 

EUA authorized comparators as long as they are high sensitivity molecular 

tests with an extraction step. Thanks, Toby.

Toby Lowe: Thanks Timothy. And that leads perfectly into one of the next questions which 

was actually about the BioFire DeNovo that was recently granted. So as I’m 

sure most people have seen BioFire was issued a De Novo for their extended 

respiratory panel and includes SARS-CoV-2. And this question is asking 

whether their test is now the only one that can be used as a predicate for 

subsequent submissions by other manufacturers.
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So since BioFire was entered a De Novo they are currently the only legally 

marketed predicate for a 510k submission until subsequent tests are also 

cleared through the 510k pathway.

So for future 510k submissions BioFire is currently the predicate to use there. 

But for your comparator, for your clinical evaluation you can use BioFire but 

you also can use an EUA authorized highly sensitive RTTCR assay for the 

clinical evaluation as well as for EUA requests.

And we do recommend that if you intend to pursue the 510k pathway that you 

submit a pre-submission to discuss your proposed validation strategies and 

your comparator methods.

Timothy Stenzel: And I would just add, since we have not granted a serology test or an antigen 

test that those initial applications would be through the De Novo pathway.

Toby Lowe: Yes. Great. Thanks. And continuing on the BioFire path, we have a question 

about an EUA under review, an EUA request under review for a similar 

expanded respiratory panel RSV and SARS-CoV-2. And whether they need to 

figure out how to perform clinical studies this year even though there is the 

low influenza prevalence in light of the BioFire De Novo or whether the 

EUAs would be able to remain in place.

And so I do want to clarify that the BioFire De Novo does not impact any 

EUAs other than their own for that identical test which we revoked concurrent 

to granting the De Novo for the same test.

BioFire’s other EUAs including the point of care test as well as EUAs for 

other - where other developers were not impacted.
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We obviously can’t anticipate when the public health emergency will end but 

we are committed to helping to ensure that the public has access to a wide 

variety of test of options for COVID-19. And we do intend to continue to 

review EUAs to address the public health needs.

And continuing on the influenza and RSV line of questions, we have a 

question asking whether FDA is open to the use of archived specimens to 

pursue clearance of an extended respiratory panel to include flu A, B, RSV

A&B and SARS-CoV-2.

So generally to evaluate the clinical performance of your multi-analyte test a 

prospective clinical study should be conducted. Considering the public health 

needs in the current emergency, a clinical performance study in support of 

your EUA request may be conducted at one site testing archived, positive and 

negative clinical samples with known specimen types.

The pre-selection of archived positive samples should represent a range of 

viral load or CT values including low positive samples near the assay’s cut 

off. And since this is typically for a device that has not been -- excuse me --

FDA cleared for the respiratory pathogens included in the test and it’s likely 

that the test will be used in patients with respiratory symptoms in lieu of an 

FDA cleared respiratory panel, 

we do intend to include a condition of authorization that you conduct a post

EUA the post authorization prospective clinical study that would include a 

minimum of three sample collection sites and three testing sites prospectively

in patients with general respiratory symptoms.

Timothy Stenzel: And if someone is interested in pursuing a full authorization of an EUA panel 

we would still allow some archived sample use, however, we would ask for 
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that prospective clinical study for the conversion to a full authorization and 

collect as many positives as feasible. You know, we understand that some 

respiratory viruses especially flu are very low in circulation even during peak 

respiratory season during the pandemic.

And so the recently authorized BioFire and De Novo in the special controls 

does speak to this use of archived samples if the prospective study 

demonstrates low prevalence of certain viruses. Thank you.

Toby Lowe: Thanks, Tim. The next set of questions that we received is regarding the 

difference between EUA requirements between prescription use lateral flow 

antigen tests and non-prescription use lateral flow antigen tests.

So generally the recommendation for analytical and clinical validation are 

included in the EUA template. And we expect that the clinical evaluation be 

conducted in the appropriate setting such as point of care or at home 

depending on the proposed indication.

If you are seeking an asymptomatic screening claim you should validate in 

that population. Though as we have discussed in the supplemental template 

issued last week you may request a serial screening claim based only on 

symptomatic validation.

Additionally for tests intended to be performed by lay users you should submit 

usability data. And for OTC tests for the lay user who will also receive and 

interpret the results themselves, we would expect user comprehension data.

The question further asks if data from asymptomatic individuals for an OTC 

claim could be done post-authorization? So generally for non-prescription 

tests we do expect that they will include a claim for asymptomatic screening 
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since there would not be a healthcare provider involved to determine if the 

individual has symptoms or is otherwise suspected of COVID-19.

And generally we do expect to see that symptomatic - sorry, the asymptomatic 

validation pre-authorization. But in the case of serial screening per the 

supplemental template we will consider authorizing that claim with a postauthorization condition to establish performance with asymptomatic 

individuals when your PPA is at least 80% in symptomatic individuals.

We received a question about high volume and low volume settings or tests

for a lateral flow test. And we have discussed this previously where we do 

prioritize review of EUA requests where authorization would significantly 

increase testing capacity such as tests that reduce reliance on test supplies and 

try to report widely distributed tests to address public health needs.

We can’t unfortunately provide specific numbers of what we consider to be 

high or low volume or throughput. But if you need help determining whether 

your test would be considered high testing capacity we recommend that you 

reach out through the EUA mailbox with information about the features of 

your test.

Timothy Stenzel: I would add that lateral flow devices are one at a time devices and if they are 

being performed in a high or moderately complex lab they are not high 

throughput tests. And so their prime value in the pandemic is in the point of 

care or potentially the home setting. So that’s where we focus our priority 

reviews for lateral flow devices.

Toby Lowe: Thanks, Tim. We received a question about over the counter test kits and 

whether or not they are required to report the results to public health 
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authorities. And we do encourage developers of home tests to include 

mechanisms for reporting results to public health authorities.

We don’t intend to hold up authorizations of home tests that do not have this. 

But we have in some cases included the development of such a mechanism as 

a condition of authorization for a home test that we have authorized before 

that test has been available.

Timothy Stenzel: Yes. And that’s some period of time after authorization. And absolutely we 

see the reporting of data from all types of tests as useful for managing this 

pandemic. And any method that can, I don’t know, streamline the reporting of 

that would be helpful. And HHS administration have been working on 

pathways to do this and they continue to make advances. And we would refer 

you to them and their announcements on the availability of reporting features. 

Thank you.

Toby Lowe: Great. And then the last question that we will go through from the pre-sent 

questions is regarding assay controls for home tests and whether external or 

internal controls are needed for at home tests. And so we do generally believe 

that external controls are important for quality control and training, but we 

don’t think that they are typically needed for at home tests.

However, we do recommend that at home tests have an internal control to 

ensure that the test results are valid. And with that I think we can turn it over 

to live questions.

Coordinator: Thank you. We will now begin the question-and-answer session. If you would 

like to ask a question please press star 1. Please unmute your phone and 

record your first and last name clearly when prompted - your name is required 

to introduce your question. To withdraw your question you may press star 2.
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Once again at this time if you would like to ask a question please press star 1. 

One moment please for our first question. Our first question is from (Parvan), 

your line is open.

(Parvan): Hi, thank you for doing this. I’m, (Parvan), I’m with GreenRoad Diagnostics. 

We have been added to the commercial manufacturers’ notification list in late 

December and been under high throughput EUA review ever since. However, 

this Monday we received mail from the FDA team saying they are no longer 

under active EUA review as we are not high throughput.

We have a couple of questions but we are just adding more color to what we 

are doing. Excuse me. Our test is a direct saliva RT-LAMP assay with MRA 

detection which allows for massive (unintelligible) for ultra-high throughput. 

It does not require extraction which greatly reduces total time from sample to 

answer. We chose 96 well plates as a base crossing unit.

The manual steps required are equivalent to manual handling with high 

throughput RT-PCR systems, so we classify that’s high throughput. There 

seems to be a guidance where 384 well plates are required instead of 96.

There also seems to be a guidance for automation to be included directly in 

the EUA.

Now coming to my questions, the first one, will 96 well plates read 

simultaneously meet or exceed automated 384 well plates, what is the 

consideration for qualifying as high throughput?

The second question - sorry. Go on.

Timothy Stenzel: No. No. Go ahead. Ask your second question.
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(Parvan): The second question is, where the throughput of the manual process meets or 

exceeds the throughput of the automated system, should automation be 

included in the EUA or should a separate EUA be submitted?

Timothy Stenzel: So this is a very specific question for your specific technology and we have 

invited all developers to send an email to the templates email address or 

through a pre-EUA process to address whether or not their tests or a specific 

test will meet our current threshold for priority review.

And if you have been unable to get your question answered, please send 

another email to the template’s email address and ask that Toby and Tim be 

copied and we will respond as quickly as possible to you about your specific 

situation.

(Parvan): Thank you. We actually just did that. Just since we got the mail on Monday 

and we were not able to get in time to submit the question early on for this 

town hall. The one thing we want to clarify is because of the difference 

between 384 and 96 well plates, if you use 96 well plates but if our throughput 

is meeting or exceeding how would it be considered? That’s something we 

were not clear on?

Timothy Stenzel: Yes. So you have a very assay specific question here and its best handled 

offline and not on this call so that we can understand the details of your test 

and see if it doesn’t meet our threshold and give guidance for modifications 

you might be able to make. So your questions are very focused on your 

specific test and that’s best handled offline as the leader of the call has 

suggested at the beginning of the call.
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So please go to the next - please make sure that Toby and I are included in 

your email correspondence on this, and we will make sure that you get a 

response. All right. Thank you. Let’s please move on to the next caller.

Coordinator: Yes. Our next question is from (Karbamody Vankar), your line is open.

(Karbamody Vankar):Good afternoon. Thanks for taking my call. I have a question related to the 

serology template that was put last week March 17. I’m looking at the clinical 

agreement study section of the template and either suggesting the section A, 

the comparator as RTPCR test.

Taking this RTPCR test as a comparator was there early on but now that we 

have so many EUA authorized serology tests available, is it possible to use a 

EUA authorized serology test as a comparator rather than RTPCR test? Is 

there any rationale in requiring only RTPCR tests as a comparator? Thank 

you.

Timothy Stenzel: Yes. Thanks for that question. We continue to believe that RTPCR high 

sensitivity molecular test with an extraction step remains the best comparator 

for all comparisons whether they be serology, antigen or molecular. And the 

serology test can have lower sensitivity and, you know, in the authorized. So 

for now we are continuing with our recommendation that molecular be the 

pathway.

But as always these are recommendations and if you want to pursue 

something that’s not recommended and get a preview on our thoughts about 

that validation. You can send the pre-EUA to the template’s email address. 

Thank you.

(Karbamody Vankar):Thank you.
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Coordinator: Thank you. Our next question is from (Elaine Allan), your line is open.

(Elaine Allan): Yes. Hi, thank you for your time that you give us every week. It’s very much 

appreciated. My question concerns a comment made last week regarding 

clinicians ordering off-label testing to look at the response to vaccine.

Last week FDA stated that after investigations that have been it turned out that 

the vaccine generated an antibody to the spike protein but the serology test 

was directed towards the end point. So therefore the serology test was not a 

good candidate to look at the vaccine response.

My question is, would a serology assay that looks at the spike protein 

potentially be a candidate for vaccine response?

Timothy Stenzel: So I think this may be vaccine specific and if a test wants to make a claim that 

they can detect a specific response then a clinical study, you know, should 

demonstrate that. So, you know, we don’t object clinicians ordering tests offlabel. They do that fairly frequently. They prescribe drugs off-label.

When they do that they are taking more responsibility obviously for the use of 

that test or possibly drug. And we just wanted to make sure that they were 

aware that not every serology test that we have authorized can detect an 

immune response to every one of the vaccines we haven’t analyzed that. But 

clearly if there is a mis-match then you would theoretically know that an end 

protein management test would not be positive if the patient has only received 

a spike protein vaccine.

And again we are open to submissions that at least want to clarify this and as 

this goes forward and clinicians use serology tests in this manner even though 
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they are not authorized for this, we want to make sure that its clear, you know, 

that, you know, certain tests could potentially be used.

So I’m not sure how we are going to do that but we are open to response to 

what test developers want to do in that regard and so it’s probably best to 

come in with a pre-EUA with something you would like to do and suggest 

along with some sort of study design.

(Elaine Allan): Okay. So it wasn’t a sweeping comment that all serology tests were not 

candidates. It was just that particular issue or situation.

Timothy Stenzel: Yes, it’s a theoretical mis-match. But again you can have a spike protein 

vaccine - not again but I would say that you could have a, you know, a spike 

protein vaccine that may not overlap entirely or completely or even at all 

perhaps with a spike protein. An antigen test depending on what’s the antigen 

in the vaccine and what’s the antigen in the serology test. So just because it...

((Crosstalk))

(Elaine Allan): I understand.

Timothy Stenzel: ...make a blank statement that a spike protein serology test, you know, works 

for a given spike protein vaccine. We would like certainly to make that claim 

and we would like to look at data that supports that.

And we are busy, busy with a number of things that are in the works to further 

expand testing and we always have more than enough to do and Toby has on 

her list the communication around serology tests and vaccines. So for more 

details about that you can come in and ask questions or you can wait on her 

potential communication in the future once it gets cleared.
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(Elaine Allan): Okay. Great. Thanks so much.

Coordinator: Our next question is from (Tim Snider). Your line is open.

(Tim Snider): Hi, thank you. My question is around the clarification on the BioFire De Novo 

and just want to make sure I understood properly. Is that De Novo now the 

predicate for all COVID NAT test or is it only for multi-plex respiratory panel 

type NAT tests that include COVID?

Timothy Stenzel: So I will let Toby fill in any gaps here but it’s a predicate for all SARS tests. It 

can be used for full authorization comparisons and it also can be used for 

EUA authorization comparison. We are going to continue to be open for other 

comparators to be used for EUA authorizations as well as for full 

authorization because there may be not full availability for everybody to get a 

limited number of fully authorized tests until we get to that point.

Once we get to that point where there is plenty of availability of fully 

authorized tests, you know, we will see what we do at that point.

(Tim Snider): Okay. Thank you very much.

Toby Lowe: And I would just add that the - yes, until there are more 510(k)s authorized for 

SARS-CoV-2 whether as a single analyte or a multi-analyte test the BioFire is 

the only predicate for a 510(k). But as Timothy said, we do, you know, we 

will consider other high sensitivity RTPCR tests as the comparator for your 

clinical evaluation.

But for the 510(k), you know, paper submissions the BioFire would be the 

predicate of record.
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(Tim Snider): Okay. Thank you.

Timothy Stenzel: You know, that’s a detail for those schooled in regulatory submissions about

how you go about doing that but you can, you know, when you submit your 

510k you list the legally authorized predicate that can be applied to the 510(k). 

Next one.

Coordinator: Our next question is from (Kristen Bankard), your line is open.

(Kristen Bankard): Hello. Thank you for taking my call. I have a question regarding the serial

testing, the asymptomatic post authorization clinical study. Does the FDA 

have standard criteria for PPA and NPA specifically for molecular tests for 

that clinical study?

Timothy Stenzel: So, you know, for molecular tests in symptomatic populations, you know, are 

above the 95% PPA in comparison to another EUAS authorized test. We 

would expect that, you know, a once weekly serial testing program with a 

molecular test would yield a very high PPA even in the asymptomatic 

population.

Based on the recent data that has been a pre-print out, of a study that was 

sponsored by NIH and also other data that we have available. So we don’t 

have a pre-set threshold for the asymptomatic screening performance because 

we just haven’t seen enough data and we haven’t seen other than the research 

study that was performed, we haven’t seen to my knowledge a serial testing 

submission so we could see what the data looked like.

So once we get experience on what tests generally are able to achieve and 

there may be differences between molecular and antigen tests for example 
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because antigen tests are typically less sensitive than molecular tests it was 

difficult to set an expectation.

But obviously ideally would like to see all serial testing programs in both 

symptomatic and asymptomatic be above an 80% PAA if possible but we are 

not setting a firm recommendation at this time.

(Kristen Bankard): Okay. Thank you.

Coordinator: Our next question is from (Emily), your line is open.

(Emily): Hi, my question is regarding the enrollment of individuals age 65 and older 

into a clinical evaluation trial for a molecular non-lab test. Our current 

protocols are aimed to exclude all individuals who have received the COVID 

vaccination but in the guidelines the target suggests that 35% enrollment of 

people who are 65 and older.

Given that the large majority of these individuals have already received a 

vaccination, we plan to remove this exclusion from our trial. The question is, 

would the preference be to remove the vaccination exclusion for all subjects 

or just individuals over the age of 65?

Timothy Stenzel: So for what type of test is this? A serology test?

(Emily): This is for a molecular test.

Timothy Stenzel: Molecular test. Toby, I’m not sure that I’m prepared to answer that question. 

Maybe we write it down and respond unless you feel that you can handle that 

question today.
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Toby Lowe: No. I think I would suggest that you send in your proposal with additional 

details about your proposed trial and then we can respond specifically to your 

proposal.

Timothy Stenzel: And, you know, I think we will take this back and discuss and hopefully 

provide a sort of a clear answer next week on the call.

(Emily): Okay. Thank you.

Coordinator: Our next question is from (Perchim Greg), your line is open.

(Perchim Greg): Hello. Can you hear me?

Timothy Stenzel: Yes, we can.

(Perchim Greg): Yes. So I’m from the X, Y, Zee Laboratory, we are in the process of 

validating the flu and the COVID convolute of multiplex tests. The question is 

when we started we were thinking it would be very easy to get a clinical 

sample with influenza A and B infection. But the fact is its very difficult. And 

my question is, is it okay for us to use the - inactivated virus of influenza A 

and B to make a contrived sample for the validation?

Timothy Stenzel: So I just want to clarify, so you are looking to validate an EUA authorized 

validate a panel test for EUA authorization and you want to know if you can 

use contrived non-SARS respiratory viruses?

(Perchim Greg): So contrive the influenza A and B so we are validating the multiplex test for 

the COVID and influenza A and B channel.
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Timothy Stenzel: Yes, because there is already FDA cleared influenza tests on the market, we 

are wanting to make sure that performance of EUA panel tests that are new 

that we haven’t seen before for flu A and B that they perform at an acceptable 

level and we are asking for archived samples.

This is sort of the first time I have heard that archived samples are not 

available for flu A and B. You can always send an email with a pre-EUA to 

our template’s box. But until we know what flu A and B banks are depleted 

for clinical samples, we would still like to see archived samples prior to EUA 

authorization.

And then as we discussed we would ask to see a prospective study postauthorization to be able to be considered for EUA authorization. So you 

explain your challenges in trying to obtain these archived samples.

But again this is an area where we have already cleared flu A and B and they 

are available in the market and so we are being cautious.

(Perchim Greg): Okay. Thank you.

Coordinator: Our next question is from (Annie Wright), your line is open.

(Annie Wright): Yes, hello. I had a question regarding stability testing for - in the guidance, 

you know, it describes stability testing to include transport and shipping. So I 

am just wondering if an EUA’s expectations of the FDA to also include some 

sort of worst case shake and bake scenario for the shipping and handling 

portion? Or can we just basically have a shipping study that basically shows 

the transportation of our device without the actual simulated shaking and 

baking?
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Timothy Stenzel: Toby, I’m not sure how much the templates go into detail on this. But we are 

satisfied with an in-lab stability testing, looking at for EUA authorization 

looking at temperature stability.

And so now since we can expect that this pandemic will go year-round or the 

testing at least for SARS will go year-round going forward -- we expect to see 

potential extremes or heat or high temperatures and the extremes of frozen 

temperatures on shipping stability.

Toby, do you have anything else to add on stability testing?

Toby Lowe: No. I am also not completely sure how much detail is in the templates. I 

would have to pull it up on that but if you do have further questions beyond 

this you should definitely send it in and we can take a look.

Timothy Stenzel: Yes. So for full authorization we would potentially look at some things like 

drops and things like that but have since pulled that back for EUAs since the 

bar can be lower for EUA authorization. So I believe but double check that 

it’s just the temperature extremes on shipping.

And for the potentially extreme time for any return, we also ask for stability 

testing on any home collection device to make sure once it enters into 

commerce that it has an expiration date and that we know what that is.

(Annie Wright): Okay. Yes. To assure stability. Okay.

Timothy Stenzel: And so stability for that is good for the initial authorization we may - and then 

of course real time stability after that.
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(Annie Wright): So just really quickly, the extreme temperatures are you expecting the data as 

part of the EUA submission or can that just be like a protocol provided and 

then it could be like an ongoing study?

Timothy Stenzel: So for a home collection situation we are asking to review that shipping 

stability study prior to authorization. If you were already using something for 

which we have authorized and managed for a right of reference such as the 

Gates collection study. You could potentially if you use the sort of exact same 

things you can potentially fall under that right of reference that gates has 

offered and you can ask about that in the submission.

But if you have a specifically proprietary unique device then those stability 

studies would need to be repeated.

(Annie Wright): Okay. But do they need to be the data we submitted in any way or can be part 

of like the real-time data where you can say, okay, we are going to be doing 

this. This is what we are proposing to do.

Timothy Stenzel: No. Actual real-time data - so I was talking about two different things. Realtime is for the collection capability testing, not shipping. And for that we 

would want to see accelerated stability testing of your collection kit. And then 

we also want to see the shipping stability to make the authorization for - as 

part of the authorization required recommendations for a home collection kit.

(Annie Wright): Okay. What about for professional use, provider care?

Timothy Stenzel: So for professional use these are collection kits. Toby, you can help me out 

here. But if a kit makes a claim about use of the collection kit in for SARS or 

SARS plus a panel we would treat that as a device and we would ask for and 
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obviously to be shipped and so we would look at the same sort of things there.

Toby, did I get that right?

Toby Lowe: Right. If it’s some, you know, proprietary collection device we would expect 

to see information on the specific collection device including some of the 

stability data if you are, you know, simply using previously, you know, widely

marketed, you know, a standard nasal swab and things like that then we are 

not likely to have additional questions.

(Annie Wright): Okay. Thank you so much. Thank you.

Coordinator: Our next question is from (Shannon Clark), your line is open.

(Shannon Clark): Hello, this is (Shannon Clark) with UserWiseConsulting. We specialize in 

human factors testing. Are you able to hear me?

Timothy Stenzel: Yes.

(Shannon Clark): Good. So with regard to the home use or non-laboratory use template for 

antigen and molecular testing, on our side we have been getting feedback on 

our submissions in relation to the age range. And I just wanted to confirm that 

there is a typo in this template where under the clinical evaluation section 

number eight it says, the parent or legal guardian collects a sample from a 

child e.g. aged 3 to 13.

And then just a couple paragraphs later it says the study population should 

include individuals across all ages 2 years to 65 plus years. Can you confirm 

that age range that you are looking for an OTC designation is in fact 2 to 65 

years and that the labeling shall specify that or is 3 to 65 years adequate?
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Timothy Stenzel: Thanks for pointing that potential typo here. Yes, the intended use population 

and, you know, we would like to see data for age range is 2 to 65 I believe, 

not three. And for self-collection in that population we typically say age 14 

and above can self-collect and below that a parent, guardian, adult would 

collect.

(Shannon Clark): And I did misspeak, its 65 plus. Is there an upper age limit?

Timothy Stenzel: So, you know, so what we want to see is that sort of age groups are included. 

So I would like to see folk’s aged 2 to 14, you know, collected by a parent, 

guardian ort an adult. And then...

(Shannon Clark): Two to 13.

Timothy Stenzel: Yes. And then above 14 to above 65, you know, we would like to see, you 

know, obviously there is different potential issues in some groups so I would 

to see a good range so, you know, include those who are 65 plus and typically, 

you know, those we enrolled in age 14 to 65 is in typically depending on how 

many enrollees you have in your study you are going to see a good range on 

that. But make sure you have got representatives of those below 14 and those 

above 65 and then probably have plenty between the two.

(Shannon Clark): Thank you.

Coordinator: Our next question is from (Jackie Chen), your line is open.

(Jackie Chen): I have a question about the performance evaluation in particular the emerging 

viral mutation monitoring plan. And my question is this expected for 

manufacturers who already have an EUA? And if so, can you share with us 

some examples on how they address that and how these manufacturers 
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monitor and deal with any new and emerging viral mutations for a serology or 

a neutralizing antibody test?

Timothy Stenzel: Okay. So it is something we have asked all test developers whether they have 

been EUA authorized or not to do, to have a monitoring plan in place. For 

those who are under review now or submitting in the future, we would want to 

see that plan. We are not asking manufacturers who have already been 

authorized to come back in with a plan submission but to have a plan in place 

and to act upon it.

But for those that are a new submissions we will be asking about that for all 

assay types and, you know, knowledge of your specific test is needed to 

address any potential issues. Molecular tests are relatively straight forward in 

that, you know, the sequence of the primers and probes, you can do 

calculations around melting temperatures and know what your cycling 

parameters are or your isothermal parameters are. And determine with some

modeling, simple modeling, whether or not your assay potentially could be 

affected.

Serology tests are more challenging. We are all current in serology testing in 

review, we are now asking for the antigen sequence that you are using and we 

are logging that into our database. Obviously it’s an amino acid sequence and 

so we would be scanning the nucleic acid sequence database for SARS for any 

amino acid changes within the antigen portion of the serology tests and we 

would ask developers to do the same for antibody tests - for serology tests.

For antigen tests there is a different pathway. Developers would need to 

understand the characteristics of the antibodies that they use in their antigen 

test and know the map of, you know, the antibody binding to the virus which 

is specific for every type of antibody that’s monoclonal.
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Polyclonal will have, you know, different things to look for. But and there it 

may depend on, a polyclonal antibody, it may depend on what the antigen was 

used and the sequence of that antigen to raise the antibodies for that antigen 

test.

So every test developer has some different things that they can do and we are 

just asking that they come in with a plan. It all starts with the specific 

knowledge of your own test and examination of sequences in the US 

circulating sequence database. I hope that’s helpful.

Coordinator: Great. And at this time I would turn things back over to Irene.

Irene Aihie: Thank you. This is Irene Aihie. We appreciate your participation and 

thoughtful questions during today’s town hall. Today’s presentation and 

transcript will be made available on the CDRH Learn Web page at 

www.fda.gov/training/cdrhlearn by Friday April, 2. If you have any additional 

questions about today’s presentation, please email cdrh-euatemplates@fda.hhs.gov.

As we continue to hold these virtual town halls we would appreciate your 

feedback, following the conclusion of this virtual town hall please complete a 

short 13 question survey about your FDA CDRH virtual town hall experience. 

The survey can be found now on www.fda.gov/cdrhwebinar.

Again thank you for participating and this concludes today’s virtual town hall.

Coordinator: Thank you for participating in today’s conference. All lines may disconnect at 

this time.
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03-24-21/12:15 pm ET

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END