FDA Virtual Townhall

Moderator: IRENE AIHIE

09-09-20/12:15 p.m. ET

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FDA Virtual Town Hall Series –

Immediately in Effect Guidance on 

Coronavirus (COVID-19) Diagnostic Tests Moderator: Irene Aihie

September 9, 2020

12:15 pm ET

OPERATOR: Welcome and thank you for standing by. At this time, all participants are on 

listen-only mode until our question-and-answer session. At that time, if you 

would like to ask a question please press star then one. Today’s conference is 

being recorded. If you have any objections, you may disconnect at this time.

And now, I would like to turn the meeting over to Ms. Irene Aihie. You may 

begin. 

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

and Education. Welcome to the FDA’s 25th in a series of virtual townhall 

meetings to help answer technical questions about the development and 

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

Today, Timothy Stenzel, Director of the Office of In Vitro Diagnostics and 

Radiological Health in the Office of Product Evaluation and Quality, and 

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

Radiological Health, both from CDRH, will provide a brief update. 

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

today’s discussion. Please remember if we are not able to respond to 

questions about specific submission that might be under review.

Now, I give you Toby. 
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Toby Lowe: Thanks, Irene. Hi, everyone. Thanks for joining us again this week. I just 

have a couple updates this morning. We added a new question-and-answer to 

our FAQ page and updated a few of the existing questions.

The new question is regarding leveraging validation data that has already been 

reviewed by the FDA for another test. We’ve had a lot of questions about the 

proper way to do that and proper way to use or right of reference. So we 

added some additional information about that to the question. And we also 

updated a couple of the questions to add information about the CDC multiplex 

tests because CDC has the right of reference to the performance data in their

EUA for their Multi-Analyte Respiratory Panel. So we’ve also had questions 

about that and added information there. 

And we updated a couple of the questions in the testing supply FAQ section, 

specifically the questions related to extraction platforms and instruments for 

use with the CDC singleplex test. 

And that’s all that I have today. So I’ll turn it over to Tim for his update.

Timothy Stenzel: Thank you, Toby. And welcome again, everyone, to this weekly call. We 

hold this call weekly to assist all developers of COVID-related tests to assist 

them in explaining any of our recommendations, to listen to concerns that we 

can sometimes address immediately or take back for consideration. It is an 

ongoing effort and extension of what we do day-in and day-out, every day of 

the week, and nearly every hour of the day in working with developers. 

So again, welcome. We are committed to being transparent and to giving us a 

direct response as we can on the effort to help. I don’t usually note up-to-date 

the number of authorizations we’ve made, and I make this as long as these 

calls go on at least a monthly update. To date, we have authorized 243 tests, 

and it includes 195 on molecular diagnostic tests, 44 antibody or serology 

tests, and four antigen or direct antigen rapid tests. 

We definitely are interested in seeing more submissions for the direct rapid 

antigen tests. We just haven’t seen as many of those as we have seen in the 

others, and that’s reflected in the relative number of authorizations. However, 

we also in addition to these authorizations, offer very flexible policies that 
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have allowed more than a hundred other tests, frankly hundreds of tests to be 

on the market while their EUAs are under review and consideration. So in 

total, the amount of tests that are in the market undergoing review or already 

authorized are in the many hundreds. 

I did want to also open up that we are eager to authorize as many antigen tests 

and molecular diagnostic point of care and home tests as possible. We have 

provided templates with our recommendations for both point of care antigen 

and molecular assays as well as in the non-lab or home situation. Our 

templates provide recommendations for validations. If you have alternate 

approaches, please engage with us through the cdrh-euatemplates@fda.hhs.gov email address and/or provide us with something to 

assess through pre-EUA submission. 

With regard to point of care tests, we would like to further assist developers in 

the pre-market validation period by opening, further opening up the chance for 

developers to use banked samples for their point of care studies. If the 

technology is amenable to that where they can use banked samples, then that 

may be a very good approach pre-market. 

We do ask that and work with the member of our team to define your study 

plan because we would like to mimic as near as possible those samples being 

handed off to a point of care tester in a manner similar to which they would 

normally see patients in the clinic and do an actual prospective collection and 

test so that we can mimic a busy clinical workplace and assess the 

performance of the test. 

So that is the loosening, further loosening under an EUA situation pre-market. 

There may, of course, be some post-market studies that are likely to be part of 

such an authorization. 

Similarly, we have heard from a lot of developers that accumulating 

asymptomatic samples for asymptomatic claims or over-the-counter tests has 

been a little bit more challenging than expected. So there are two ways that 

we suggest that can aid in the accumulation of asymptomatic patients. One is 

to team up with any of the large screening and/or surveillance programs, I’m 
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looking at large populations. Of course, this is being done on many college 

campuses across the country. 

And if they identify a patient in their screening or surveillance, that’s 

potentially a perfect opportunity to enroll that patient or that residual sample 

into the clinical study for asymptomatic claims. So that can be accomplished 

in a number of different ways. One is that it’s banked samples can be used for 

your device from those testing efforts. And you can simply of all your local 

authorizations are achieved to use that sample for development of a 

commercial product allowed then you can use that banked sample.

The other thing you can do is potentially call back any positives for recollection. So we have been working with recently, very recently, with some 

who have tried to utilize this approach. And there has been some success in 

this. So we wanted to make that further awareness available to all developers. 

We also would like to start something new. Again, this is a pre-market 

validation assistance. We’re open to, in addition to having a minimum 

number of asymptomatic patients pre-market, sometimes it’s only as few as 10 

or 20. We ask there be a minimum of 10 asymptomatic patients enrolled and 

tested. If in the case that 20 maybe required which is the most common 

number of samples that are asymptomatic to be required, we’ll allow a 

minimum of 10 pre-market and the other 10 could be matched symptomatic 

samples and the matching process should be worked out with a member of our 

team but in general we’ll be trying to find samples that reflect the viral loads, 

or CTs, or viral levels of those 10 asymptomatic patients who have been 

enrolled.

If the requirement is for more than 20 asymptomatic which is in some cases 

where developers only want to seek an asymptomatic claim, there may be 

requirements for 30 asymptomatic samples and we are going to allow 15 of 

those 30 to be supplemented by symptomatic in the pre-market.

Again, with the point of care studies there maybe requirements post-market to 

bring the total up to the recommended amounts. In both cases, we will 

obviously allow enough time for those studies to be completed post-market. 
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The other thing I wanted to mention is that this morning the center director 

and I have published an opinion piece in The Hill. We hope you find our 

comments welcome. They are on all along the lines of what I just mentioned, 

our flexibility to adapt to the changing situation, adapt to the needs of 

developers and to speed access to technologies that will help. A lot of it has 

to do with point of care and or home type testing. We are very open to all 

developers who come to us with these ideas, and their tests. 

As I said earlier and from an opinion piece, our recommendations are just that, 

recommendations. The FDA is always open to alternative proposals from 

developers and we’ll continue to consider those. There could be significant 

trade-offs and test accuracy that maybe appropriate where the need for 

availability and fast results is not being met. 

So for one example where our recommended levels of sensitivity may not be 

achieved with a single test result in a home situation, maybe with the paper 

strip test. Strategies utilizing serial testing, for less sensitive tests, could be 

deployed. Regarding serial testing, I mentioned this last week I believe.

For example, what if the test had a 70 percent sensitivity? I also want to go 

into further detail about what we mean by 70 percent sensitivity. Let’s just 

say that 70 percent sensitivity is what can be achieved with one test result. 

Well perhaps with a two-pack, two test results you can achieve a greater 

sensitivity together and maybe on a day one, day two, or day one, day three 

strategy. 

So the sensitivities can be such that one or the other being positive gives you a 

positive result. We are open to that kind of testing format to see that we’re 

capturing, and this is where I’ll go in to what we mean by sensitivity. In some 

senses, the absolute LOD of an assay doesn’t matter as much especially in this 

home situation where you’re trying to find folks who are carrying a level of 

virus that can infect others.

So we typically think for symptomatic patients that the first five to seven days 

are some of the peak days for potential for infecting others with the virus. 

There’s in all likelihood a very similar window for those who are without 
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symptoms who are infected to start shedding virus and then eventually tail-off 

and are no longer shedding significant or any virus. 

We are really looking and as we’ve authorized our direct antigen tests, some 

of them have been authorized for five days post-symptoms because those are 

either the days that were studied in a clinical trial or those are the days at 

which performance was high enough to authorize. 

So some less sensitive tests may fall off more quickly after that five day 

period. That can be OK. We do want to see adequate sensitivity during those 

peak periods of virus shedding when patients are at most risk of being able to 

infect others. We think that by identification, of course, those individuals and 

isolating them, and treating them as needed we can do great good in reducing 

the incidence of new cases in the U.S.

So with that, we will now turn it over to questions and answers. 

Operator: Thank you. As a reminder, if you would like to ask a question please press 

star, then one and record your name clearly when prompted. 

If you need to withdraw your question, you may do so by pressing star, then 

two. 

Our first question comes from (Cory Yekel). Your line is now open. 

(Cory Yekel): Hi. Thank you for taking my question. We are currently authorized for 

molecular SARS-CoV-2 test with use of our at-home collection kit. We are 

also interested in pursuing a new EUA for a COVID-Flu multiplex test. Can 

FDA comment on authorization of at-home collection kits for COVID-Flu

multiple tests, and what is FDA’s expectation for data needed to support athome collection with COVID-flu? 

Timothy Stenzel: Yes, I’m not sure that our home collection template covers the multi-analyte. 

Toby maybe able to fill on this. However, we have provided some helpful 

hints and suggestions for, and recommendations for validation in the 

molecular template for kit manufacturers. 
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So I would refer to that and if you want to put together some proposals that we 

can consider and then send it in to our email address or as a pre-EUA as an 

amendment to your current authorization. We will welcome that dialogue 

with you. It is something that as we head into the flu season we’ve already 

authorized some panel tests and obviously we want to authorize many more in 

addition to that.

Operator: Thank you. Our next question comes from (Oriana Hawkins). Your line is 

now open. 

(Oriana Hawkins):Thank you. So my question is, what is the FDA’s stance on using multiple 

high-sensitivity RTP-CR assay systems for comparators rapid antigen tests, 

clinical performance validation? So for example if you have four sites 

participating in a study and just due to logistics half of the specimens go to a 

lab that’s using say a Roche covox system or half go to a lab using say Expert 

Express or Luminex, is there any challenges associated with that that you 

expect or do you think that FDA is flexible enough to accommodate that 

situation?

Timothy Stenzel: Yes, we’re absolutely flexible to accommodate that situation. Really only our 

recommendation is that you use EUA authorized high-sensitivity molecular 

tests. Though we understand that different centers would have different local 

tests that you can use as the comparator. 

You can also use multiple tests to annotate your tables so there might not be 

an ideal comparator but you can do discordant resolution with another test. 

Do discuss resolution with your contact at the FDA so that it’s done in the 

appropriate way. And then at the very least the tables in the extractions for us 

can be updated with that annotated data.

Depending on how you do the comparator and what you use for your 

reference method, it may or may not be able to have corrected results. There 

are opportunities to use corrected results, but then it does require multiple 

upfront comparator assays and a pre-specify reference algorithm in order to do 

that and use combination of tests as a reference method. 
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(Oriana Hawkins):OK. Thank you. 

Timothy Stenzel: You’re welcome.

Operator: Thank you. And our next question comes from (Daniel Marcus). 

(Daniel Marcus): Hey, guys. How are you? So very quickly, I know that on certain templates

there’s recommendation as to the sufficiency of in terms of the amount of 

samples. That one is a test for EUA, I know the recommended number is 30. 

I don’t know if that varies depending upon the fact of the circumstances or if 

that’s an absolute floors so it wouldn’t necessarily be higher. So that’s one.

And then the second question is, assuming a developer has custom kit 

components specifically a custom swab. I’m wondering what level of 

validation would be required for that to be approved or if that is something 

that can be done under design controls? Assuming you got the EUA on that 

first go.

Timothy Stenzel: Is the kit collection going to be something that’s going to be sent to a home 

user? 

(Daniel Marcus): Over time yes, but at least in the initial EUA filing likely no. So likely yes, a 

healthcare worker, at the point of care absolutely, yes. 

Timothy Stenzel: In a healthcare setting, there are things that they will be required if it was a

home collection setting and after I respond to both questions, Toby, you may 

want to add something. Typically, test developers can and frequently do kits, 

a swab, and/ or on a transport media with their tests. A number of developers 

do that so that users don’t have to go out and find these supplies. They also 

provide these so that they know that it works with their tests.

So there are certain advantages when you can provide those swabs and any 

other collection reagents with the kits. It’s not required but sometimes a nice 

to have. It depends on your assay. 
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As far as the minimum recommended number of positives and negatives, 

we’re pretty firm on that but we’re flexible on as I mentioned earlier on how 

we actually approach that. 

Early on, we allowed contrived samples and then we shifted to using actual 

patient samples when the numbers of samples were sufficient out there in the 

marketplace and in the community to be able to specimen, the recommended 

amount of 30 positives. Negatives are obviously very easy to get, 30

positives, can sometimes be challenging for some new developers who don’t 

have the connections in the community.

A number of developers have found that using certain commercial 

organizations, and CROs, to be able to provide those samples has been helpful 

to them. There’s also a number of ways to collaborate with clinics and 

hospitals, and academic centers but we can flexible to some degree on the 

sample type. 

So one of the first direct antigen tests really wanted to have a direct swab 

claim but they had adequate performance on VTM. So we are able to 

authorize the test on VTM and then later on they were able to collect enough 

of the direct swab to update their label for use of just the direct swab.

So we want to approach things in as flexible manner as we can. So there may

be some details or specifics about a specific sample type that be more 

challenging to acquire. So in some cases, we have allowed a minimum 

number of samples to be tested for an additional sample type in addition to 

something else that had the 30 positives to go into the intended use with the 

post-market commitment. So again we try to take as flexible approach as we 

can even given that the bars are really, the recommended bars are really quite 

low. 

(Daniel Marcus): OK. Yes. I’m not even suggesting to go lower, I’m suggesting, I’m asking if

there’s a scenario where the bar would be higher depending upon sample size

on one hand and then the other question that I would want to fit in very 

quickly is, is there an expectation that there’s an, there should be an IRB in 
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place for all studies or there’s no need to necessarily demonstrate it, it’s just 

part of good clinical, good practice. 

Timothy Stenzel: The IRB assessment is not a part of our standard EUA assessment. We do 

expect folks to adhere to all federal, state and local laws and regulations. So 

really that’s for you to determine to do the appropriate one. 

(Daniel Marcus): OK. Thank you.

Toby Lowe: And just to add to that, generally the studies do fall under IRBs oversight and 

so we would encourage you to talk with your IRB about what they would 

expect for your specific plans. 

Just to add a little bit on your swab question as well. Most swab or many 

swabs are exempt from 510(k) review. So they just would need to be 

registered unless did and follow the other regulatory requirement depending 

on your particular situation. If there is something particularly unique about 

your tester, about your swab, then you may want to have further discussions 

about that. So you may want to send that question and with any relevant 

details so that we can make sure that we get you the right answer there. 

(Daniel Marcus): OK. Thank you. 

Operator: Thank you. Our next question comes from (Josh Presados). Your line is now 

open. 

(Josh Presados): Hi. Thank you for taking my call. We are a molecular test kit developer and 

we have nearly completed validation of a saliva test including the peer study 

and also that background interference study because we have been using an

extractions system. 

My question is about the collection devices. Our system is based on unique 

saliva meaning it doesn’t need any sort of preservatives or guanidine or

anything like that in it. So it can be collected just in like a empty plastic tube. 

So we would ideally like to have an authorized test where it doesn’t require a 

specific collection device so that somebody who doesn’t have it could use any 
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tube. We would also like to make it easier for customers to be able to source, 

be able to provide a specific collection device that they would have. 

So what is the best pathway for us to accomplish both of those things? How 

best can we do that? 

Timothy Stenzel: So I would say the short answer is it depends. I don’t know if you’re doing 

any offsite collection, home collection, shipping or if it’s all going to be 

within a healthcare center. If it’s all within a healthcare center or a healthcare 

facility, I would -- there may be more openness to not specifying a particular 

collection receptacle and not providing it. That would -- I think that’s best 

entailed with working with one of our contacts in our office to assess how you 

might determine appropriate collection receptacles. 

So there are common receptacles used across all healthcare systems very 

common probably. So it could be as simple as providing a part and part 

number, and a manufacturer for that collection receptacle that is required say 

but not provided. 

The specifics of this is best worked out between somebody on our staff and 

you the developer. 

(Josh Presados): All right. I will write in to you. Thank you.

Operator: Thank you. Our next question, I believe the name is (Winnie Joe). Your line 

is now open. 

(Winnie Joe): Yes. Thank you for taking my question. I have a question regarding the 

asymptomatic and symptomatic tests. So basically, we are doing some 

screening under the order of medical director or clinician. So we do find 

some people there asymptomatic but have very high viral load especially in 

the young people. So I think what is the essential requirement for the EUA 

authorized to test the asymptomatic people? So we do have enough 

asymptomatic people we test them positive, is that all we need to present to 

see our assay can be used for asymptomatic or I’m just a little bit confused 

here? What other things we need to do?
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Timothy Stenzel: So you have molecular kits.

(Winnie Joe): Yes.

Timothy Stenzel: It’s already authorized and you want to add asymptomatic to your intended 

use. I believe we ask for 20 positive asymptomatics. We want those to be 

collected in an un-biased way and not cherry-picking way. They just require 

those 20 and that you show that that’s comparative performance to the 

accepted recommendations. That’s all you need. 

There are some alternative pathways you can pursue and compare CTs 

between symptomatic and asymptomatic historically. So if you already have 

the samples and you have the 20 minimum samples and they were collected in 

a manner in which is unbiased that may be all that you need. 

So I would just submit a question to probably the reviewer you worked with 

before and find out if that’s sufficient to update your intended use. 

(Winnie Joe): That’s wonderful. OK. Great. Thank you. 

Operator: Thank you. Our next question comes from (Roxanne Cheng). Your line is 

now open.

(Roxanne Cheng):Thank you. Yes, we have EUA authorized COVID-19 kits and we’re working 

on the saliva claims. So my question is that we’re able to find the commercial 

company that will collect the paired NP and saliva samples but there seems to 

be a challenge getting VTM or UTM. So does FDA approve use of CIVD 

certified VTM in such study or collection of samples for research like for our 

company? 

Then the second question I have is that for negative saliva samples, are we 

allowed to use saliva from subjects that have been tested NP negative by a 

public laboratory on the same day? 

Timothy Stenzel: Can you ask the second question again? Do you want to source negative 

saliva samples from another lab?
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(Roxanne Cheng):No, it’s actually a subject, a person has already done their NP, their COVID 

test with NP in another lab, and we want to use their saliva. 

Timothy Stenzel: Yes. I see. So they’ve had a test of record with NP and then you want to as 

quickly as possible collect the saliva sample from that patient for use. Yes, 

again our recommendation is that the test of record or the comparative test, the 

one used with NP be an EUA authorized high-sensitivity molecular test as the 

comparator. 

Then, yes, we’re open to that recollection of a sample. There’s a couple of 

things that I just want to clear with one of our staff. One is when you recollect 

a sample you obviously know whether that patient is positive or negative. So 

whoever is performing the test should be blinded to that result which means 

you should be, considering you want to be considering providing that tester 

with also negative samples so that they know that if they don’t know that all 

the samples that are coming to them are positive. So that tester remains 

blinded and unbiased in their approach. 

(Roxanne Cheng):OK.

Timothy Stenzel: Then on the first question where VTM. Of course, there are -- we have 

provided a guidance on VTM where it matches the CDC recipe. So anything 

that falls under that immediately in effect guidance should qualify even if it’s 

not manufactured in the United States. 

Then, so you can look at that guidance to see if that, the other VTM providers 

would be that. Also PBS and phosphate buffered saline, we found to be a 

very acceptable media. 

(Roxanne Cheng):Indeed, yes.

Timothy Stenzel: So that can be easily purchased for your use in your study. So those are the 

options. Toby, you may want to add something on either those but maybe on 

the VTM too, so I’ll pause. 

Toby Lowe: I think it’s mostly covered. I just want to emphasize that how you are testing 

should be reflective, how you’re testing for your validation should be 
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reflective of how you intend to indicate your test for use. So that’s something 

to keep in mind when you’re selecting a media. 

(Roxanne Cheng): Sure. Yes. OK. Thank you very much. Perfect. 

Operator: Thank you. Our next question comes from (Wendy Strong). Your line is now 

open. 

(Wendy Strong): Can you comment on the use of saliva for rapid antigen tests? Would you 

want to -- would you allow storage of saliva samples compared to matched 

PCR results? Would you consider that sufficient? Specifically, can you 

comment on the use of saliva for a rapid home antigen test? 

Timothy Stenzel: Yes. So certainly open to saliva use in any test situation whether at the home, 

non-lab, point of care or other as long as it works. So we have heard from the 

numerous developers who have not been able to make saliva work for the 

direct antigen test. So if you can do it, more power to you. We make our 

decisions based on data and not on pre-ordained facts. 

So it still fascinates me that it’s oral fluid and saliva can work as well as they 

can in some cases for the detection of SARS-CoV-2 infections. So then you 

said what about banked frozen samples. 

(Wendy Strong): Correct. 

Timothy Stenzel: So in a point of care setting, I did mention earlier in this session that we’re 

open to using banked samples and that could include frozen. Typically when 

frozen samples are used, we want to know how the frozen samples compare to 

fresh samples because the fresh samples are what would be used in a natural 

point of care setting or home setting. 

There could be situations where samples either degraded or viruses made 

more accessible by freezing. We have actually interestingly enough seen 

situations where we think freezing of a sample actually improved sensitivity 

but it’s obviously not in a standard workflow situation for any sort of routine 

testing to first freeze the sample before you test it. 
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So we do want to understand those parameters. We would probably want to 

see some minimal number of fresh samples in addition to banked samples. So 

I think some of the details should be discussed with a member of our team to 

give you a very specific feedback. 

(Wendy Strong): When you say that it would have to work, I certainly agree with that but what 

is your, what are you considering work and that kind of gets back to the 

question you touched on earlier, what sensitivity or what measure, what LoD 

would you need to see to consider saliva is acceptable? Tying that into what 

you said about a multi-pack if the claim is for doing the test several times over 

several days, how does that affect whether you consider that acceptable? 

Timothy Stenzel: Yes. As we have mentioned in our templates and as we mentioned and I have 

mentioned in the opinion contribution to The Hill this morning, we are open to 

single tests that are less sensitive if in combination They provide adequate 

sensitivity. 

I mean the most important thing is if someone has viral levels that could be 

contagious, could infect somebody else. We’re not talking about rare 

occurrence weeks after infection with very, very low potential viral level. 

We’re talking about peak period of viral transmissibility. We want to 

see good performance in that window because otherwise people would get a 

false sense of security from a negative result. 

So if combination of two tests, three tests over one to three or so days 

improves your sensitivity so that we’re making sure that we capture a 

significantly number of who can transmit virus, then we’re open to that.

(Wendy Strong): What viral load do you think would be important to detect? Do you have a 

number on that? 

Timothy Stenzel: Well, we’re starting to look at the available information we have for say CT 

results. CT results and the CAP has come out with an article saying it’s really 

hard to make these tests truly quantitative. There’s all sorts of factors that go 

into there. Probably the most important factor is adequate sample, and then 

there’s biology. So but we have seen very high CT, for some of the 
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submission in the first few days of post-symptoms. That was a little bit 

surprising to us. 

So a simple cut off for CT may not be sufficient for performance evaluation in 

that situation. So again we’re data driven. We understand the typical course 

of infection and the infectivity, and it usually means that in the prescribed 

seven days after symptoms have initiated in a patient they can be considered 

potentially infectious obviously.

(Wendy Strong): So would you consider-I mean in terms of say 10 to the 3, 10 to the 4, 10 to 

the 5 viral particles per ml, do you have a range that you believe should be 

detectable in order to detect that early infectious stage?

Timothy Stenzel: Yes. So LoD is really, really, really tough to get at and there is not an 

international standard. There’s not a really good way to assess that. There’s 

not a really good way to get a great sample every time. I was involved in the 

early days of real-time quantitative PCR development and FDA authorization 

for an HIV quant, HCV, HPV quant assays. When you have a blood sample 

which is pretty uniform, and you have a highly sensitive and linear molecular 

test which is real-time test that’s more well-developed, well-validated, You 

can start to really specify what levels matter. 

It’s very challenging with the respiratory specimen to do that. So we remain 

open and flexible. LoD is not primarily the determining factor in whether we 

authorize a test for the detection of virus or viral RNA. It’s largely the clinical 

study where in comparison to, for the period that you’re looking at, compared 

to a high sensitivity molecular test which provides the reference result for 

those say early days of post-infection to know whether a patient is infected or 

not with a SARS-CoV-2 or they have something else. So that more 

establishes the truth of the infection rather than the level of the infection. 

(Wendy Strong): OK. Thank you. 

Timothy Stenzel: I wish it were easier than this. 

(Wendy Strong): Me too.
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Timothy Stenzel: We are trying to deal with very complicated situation. Typically an assay that 

performs very well in the first five days post-symptoms then we just want to 

see if you want to go after an asymptomatic situation and we just want to see 

how it really does perform in an asymptomatic population.

As I said before, we’re willing to go as low as 10 asymptomatic samples premarket with the post-market commitment to fill in the rest. Go ahead. 

(Wendy Strong): Yes, and my last question was, at what point would you recommend trying to 

set up a pre-EUA contact with FDA? 

Timothy Stenzel: So we have provided a lot of recommendations in our templates and to say

save precious time we urge those recommendations to be reviewed. It would 

really be those questions that aren’t directly addressed in those templates 

where there’s the most value that we can add.

So I think the authorization has been made with direct antigen tests already in 

the first five days of symptoms, they’re the first two that were authorized, I 

think we’re authorized for five days. Those were sufficient performance in 

the symptomatic population. If you can show the rough equivalent to that 

kind of detection in those acquired asymptomatic infection then I think you’re 

a long way, you’re all the way there but do engage with us on the specifics. 

(Wendy Strong): Thank you. Thank you very much.

Operator: Thank you. Our next question comes from (Grace Cardin). Your line is now 

open. 

(Grace Cardin): Hi. Yes, my question is from an investor viewpoint. I realize you can’t 

mention specific companies but I’ve read from previous townhall transcripts 

that you operate on generally a 90-day window for EUAs. My question is, 

actually it’s two questions, first question, if we’re outside of a 90-day period, 

is it safe to assume that possibly that test was problematic or rejected? 

My second question is regarding the home saliva test kits. I’ve read 

something recently or heard something from the FDA that you’ve changed or 
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amended your requirements regarding reporting of those tests to authorities 

like the CDC. Could you comment on that also?

Timothy Stenzel: Yes. So I’ll take the home saliva and or any other home tests that isn’t 

performed in a healthcare facility or any facility that doesn’t have a CLIA 

certificate. Any entity that has a CLIA laboratory certificate is obviously 

required to report at least positive and negative results for COVID-19. In the 

home testing situation or non-lab testing situation where the testing is 

performed and allowed in a non-CLIA certificate setting, home would be 

perfect for this example. 

There is not a requirement under law that I’m aware of to report that result for 

public health purposes. However, there’s great advantage from there being a 

way to facilitate the reporting of that result. So we do have in our template 

not as an EUA authorization requirement. 

We do have questions around what thought the developers have given to how 

home test users for example could report results. Some are way ahead of the 

curve here and they want to help out as best as they can, and they actually 

have apps or they have a device that’s connected that could actually easily 

report these results. So but there are those who have very simple, paper strip 

tests where it may not be as easy. 

I know there are those in the U.S. government that are looking at ways to 

facilitate reporting in those situations. So again this is not something that we 

are asking as a review criteria to make a decision on an authorization for 

developers but we do welcome the ideas that developers have about how they 

can facilitate the reporting of the important results for public health purposes. 

So I think your other question has to do with what does it mean if some of --

in the EUA submission has been made and it is taken longer than we had 

hoped to make a decision. We are absolutely inundated in submissions. It’s 

why early on back in March, we basically really opened up so that developers 

could within a certain timeframe after notification for many purposes, not all 

purposes could -- once they notify begin marketing their test in the U.S. while 

we do our review. 
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Because there are so many we have had to determine a triage process and that 

triage process does move high priority tests ahead of others because either 

they require an EUA to be marketed for their intended use or they are going to 

have a bigger impact on public health. All the while for those that are allowed 

to notify, they can market. 

We do -- we attempt to do a really quick check on all submission, EUA 

submissions to make sure there are no issues of public health concern and if 

they are, we tend to try to deal with those as quickly as possible obviously. 

So I would not read into anything at all on the specific case based on the time 

it’s been with us. 

(Grace Cardin): All right. Thank you very much.

Operator: Thank you. Our next question comes from (Katie Ertley). Your line is now 

open.

(Katie Ertley): Hi, yes. This is (Katie) from (InBio Diagnostics). Can you hear me? 

Timothy Stenzel: Yes. 

(Katie Ertley): OK. Thanks a lot for hosting these sessions. They’ve been very helpful. My 

question is, what is the current expected timeline for notification 

acknowledgment? 

Timothy Stenzel: So that typically should happen in 24 to 48 hours. If it’s going longer than 

that, then I would email the team and find out what’s taking more time than 

that. 

(Katie Ertley): When you say email the team, would that be the original mailbox or a 

different contact?

Timothy Stenzel: Yes. You would get an automated reply to your email. That’s not the 

notification response email. A member of our team takes a look at things and 

assesses the suitability for notification, and then once they determine that as 

suitable then they provide you with the specific notification email. 
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Then as soon as possible after an EUA submission and my direction is within 

two weeks for that submission, you will have some contact with in the office 

depending on as priority. Either reviewer, if there’s room on a reviewer plate 

and the submission is high priority or somebody, one of our administrative 

folks who oftentimes knows a lot about test development, and I’ve directed

them to give at least weekly updates on your status. 

So but again it’s been one or two days, more than one or two days, work days, 

business days, since your notification submission then do check in back with 

the same email. Somebody should respond quickly with at least 

acknowledging your request for information and trying to find out what’s 

going on. 

(Katie Ertley): Perfect. Thanks so much. 

Operator: Thank you. Our final question comes from (Jessica Russell). Your line is 

now open. 

(Jessica Russell): Hello? 

Timothy Stenzel: Howdy?

(Jessica Russell): Can you just say a little bit more about post-market validation that you 

referenced at the beginning? And just now again. Is that just for POC or 

another context?

Timothy Stenzel: There are several situations where there can be post-market commitments. 

One is for any pooling claims. A pooling sensitivities can vary over time if 

the patient viral load shifts one way or the other. So in all pooling 

authorizations, we do have a monitoring plan that is a post-market 

commitment, that’s not necessarily a completion of validation.

And others, such as I mentioned in early antigen tests where to add a direct 

swab we only require pre-market a five swab study. They can have 30 VTM 

samples for that. This is just some example there are other similar or 

dissimilar types of post-market commitments. 
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But then the company agreed under the authorization to complete 30 direct 

swabs which they then did and they updated their intended use with the full 30 

plus, and if they had more than 30 in the end, they updated the IFU with the 

performance data on those direct swab samples. I think in that case, they 

actually removed their VTM form the label. 

So we try to be maximally flexible in what we require pre-market. So 

sometimes in offering that flexibility, we do ask for completion of the 

intended recommended studies post-market. They weren’t able to be 

completed as usually recommended in the pre-market setting. 

 

Those studies are usually, there are some negotiation on what that study 

design is and what the time period is. Those should be very relevant to the 

question at hand and to the estimated amount of time that it would take to 

complete those things. Hopefully, that answers your question.

Irene Aihie: Operator: 

Operator: Thank you. No additional questions. 

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

thoughtful questions. Today’s presentation and transcripts will be made 

available on the CDRH Learn webpage at www.fda.gov/training/cdrhlearn by 

Tuesday September 15th. If you have additional questions about today’s 

presentation, please email cdrh-eua-templates@fda.hhs.gov. 

As always, we appreciate your feedback. Following the conclusion of today’s 

presentation, please complete a short 13-question survey about your FDA 

CDRH virtual townhall experience. The survey can be found at 

www.fda.gov/cdrhwebinar, immediately following the conclusion of today’s 

live discussion. 

Again, thank you for participating and this concludes today’s discussion.

END