Transcript of Briefing by NFL Chief Medical Officer Dr. Allen Sills and Independent Medical Advisor Patti Walton on COVID-19 Testing

The NFL hosted a call with members of the media on August 24, 2020, to discuss COVID-19 testing, including test results for the August 12-20 period. The NFL's COVID-19 testing is conducted by BioReference Laboratories and results are analyzed by IQVIA, an independent third-party company. More information on the NFL and NFLPA's jointly aligned COVID-19 health and safety protocols can be found here.

Key Takeaways:


Players and personnel continue to be tested on daily basis. For the August 12-20 period:

  • ​58,397 tests were administered to 8,573 players and personnel.
  • 23,260 tests were administered to players; 35,137 tests were administered to personnel.
  • There were zero positive tests among players and six new confirmed positives among other personnel.

*Speakers: *

  • Dr. Allen Sills, NFL Chief Medical Officer
  • Patti Walton, Independent Medical Advisor
  • Jeff Miller, NFL Executive Vice President of Communications, Public Affairs, and Policy


Dr. Allen Sills: Good to be with you again as always. I want to start by announcing some of our testing results, covering the period from August 12 through August 20. During this period of time, those nine days, all our players, our tier one and tier two personnel were tested daily. I think you are aware that tier three individuals are tested weekly and any individual that tested positive obviously follows our treatment protocol which means they are immediately isolated, they are not permitted to be around the team environment, they can't access team facilities, they can't have any contact with players or personnel. And our club medical staff obviously follows up regularly.

So, here are the numbers between August 12 and August 20. In those nine days, we administered 58,397 tests. Those were administered to 8,573 players and personnel. The breakdown on those tests is 23,260 to players and 35,137 to personnel.

Pleased to report among all of those tests, and throughout that nine-day period, there were zero positive tests among players. When I say zero positive tests, meaning zero that were confirmed as positive. There were six new confirmed positives among the other personnel, and all of those were obviously treated, and again, managed according to our joint treatment protocols. So, we plan, as we've told you, to provide regular updates on our testing results but, those are our testing results from that period.

I think it is important to recognize that because that then plays into the events from over the weekend with how we and our testing partner are aware so quickly of the test situation that we had. I think it reflects the fact that our positive test rate has been so low that it immediately jumped out to us that something was going on.

I think in summary what I would say is that this has been a tremendous learning opportunity for us. We have said all along that we are going to learn a great deal as we move through this protocol because we are doing something that has never been done before. We are testing every day with surveillance tests in a very broad population across 32 different sites at a scale that has never been done before. So, as such, we know that we are going to learn along the way, and we've seen that happen already. Certainly, the events of this weekend demonstrated that fact again. As a result of what happened this weekend, our protocols will improve, we will get better, our procedures will get better, and certainly we will be better positioned to meet the challenges of operating safely in the midst of this pandemic.

Let me spend a moment just giving you a high-level overview of what happened over the weekend. Against that low positive test rate, I mentioned, we were notified Saturday morning, as we routinely are, that we had two clubs that had an unusual spike in positive tests. There were 16 tests total that came back positive. Since that represented such a change, we immediately started looking into that very aggressively with those clubs. Those clubs managed it as we would have wanted them to which is to keep everyone that was affected out of the building to retest them per our protocol and to go through the contact tracing exercises.

Obviously, that situation broadened on Sunday, to involve a total of 77 individuals, 44 players and 33 staff members. Again, those were spread across 11 different clubs but, they were all associated with one regional lab facilities that we are using. So, we immediately moved to work with our testing partner to investigate that. Again, we treated all of those as true positives because that's what we do with an abundance of caution to make sure we don't have anyone who could be infected inside our team facilities. Everyone was sent home; they were retested per our standard confirmatory steps and and through the course of the day yesterday and leading up to today, we've been going back and going through each of the steps that occurred to better understand that situation.

I am pleased to report that all of those tests, individuals, all 77, had a negative result on their confirmatory test. We believe, again, that these are what we are calling unconfirmed-positives and no one had symptoms, so it appears that none of these tests represent new infections.

As we dug into the situation with our laboratory partners, we believe that we have identified some areas in the lab where a contamination could've occurred and I'm going to let Patti speak to that in just a moment of how can a contamination occur in a lab. Suffice to say, these are really sensitive, delicate tests, which again, are subject to irregularities of this type. The key for us and for our testing partner is to quickly recognize that and to act upon that, which is what happened here.

As we move forward, obviously, the lessons that we will take away, we will speak to in a little more detail but, clearly, we have already made some changes. Our lab partners made some changes in the laboratory testing procedures with regard to trying to prevent any type of contamination again in the future. And I think we are looking together with the Players Association, and our confirmatory protocol to see if there is anything we want to update or change there. But the bottom line is this: we have to continue to treat every positive test as a potential new infection until we go through those steps. We have to remain very vigilant and make sure that we, again, isolate those individuals and go through those confirmatory steps.

All of us want to have a fast and accurate test but, our overarching goal is to have the safest possible team environment. So, when in doubt, we are always going to err on the side of keeping people out of the team activities until we can go through those confirmatory steps. So that is the sequence of events on what happened over the weekend and looking at the early results from the tests that came back this morning, it appears that there is not anything out of the ordinary. We are back down to the range of numbers that we have seen, that we reported to you earlier. We do believe that the problem has been corrected and I do have a great deal of confidence in our testing program going forward based upon the corrective actions that we've taken and that we learned.

I think this was a great learning opportunity for us, for our lab partner and for our clubs. I know that many of our club personnel saw it as an opportunity to see in real time how we treat one of these situations, particularly with regard to how quickly we need to go through our contact tracing protocols. Those all worked very well and I'm very proud of our clubs and the work that they did, again, to quickly isolate these individuals and to educate everybody on what was going on. Let me stop there an I'm going to turn it over to Patti Walton for just a moment to speak a little bit more in detail about how something like this could occur in the lab and why these sorts of contamination episodes can happen.

Patti Walton: Sure, thank you, Dr. Sills. So, this is actually a very highly complex process as we are dealing with DNA genetic material in very small amounts. There is a pre-analytical phase in this testing where the person working with the genetic material works underneath what we call, a biological safety cabinet which is essentially a hood with ventilation and it's got a shield in front so the person is not breathing into the samples. But it is very delicate work and unfortunately we sometimes have contaminations that occur and I believe that we have narrowed it down through our laboratory partner, who has spent all day yesterday doing something that we call a root-cause analysis to try and go back and figure out where the failure occurred. They believe it occurred underneath their biological safety hood. It's very easy to contaminate samples if you have samples that are positive and then you actually get it on your hand or touch the lid and then touch the next tube. You're talking about very small, minute amounts of DNA material and it is an easy process to be able to transfer that.

There are many best practices that we use in laboratories that we use to keep that from happening as far as proper PPE, we don't borrow pipets, or anything, from other areas of the lab. If the person doing the testing is sick, we ask that they not work in that area. Certainly, we have frequent glove changes and meticulous hand hygiene, robust cleaning program within the biological safety cabinet, where you clean it multiple times a day with something called a DNA Zap, which will actually kill the DNA material.

One of the things that we look at quite frequently when doing molecular testing is we look at our historical positivity rate – which means, what is our positivity rate in the past, with a particular population or just with our patient population. When we see a run that shows a positivity rate higher than that, then that's a red flag for us to stop and look and see if we have an issue. The other thing that we look at is, we want to look at what we call low positives, which means they have a high … we're looking at something called a cycle threshold and that is how many times the amplification process has to go through before it becomes positive.

So, if someone very highly infectious, they'll have a low cycle threshold. But if it's someone that's kind of right at the cutoff, their cycle threshold will be high. If we see a lot of patients that are testing positive with high-cycle threshold, then that's also a red flag to stop and actually go back and look at our run. And then, the other thing that we do is we take swabs of our hood on a fairly frequent basis and actually just swab all of the, around our hood, several times in different places and actually test those. Of course, that should be negative.

So, it's frequent cleaning, meticulous hand hygiene and watching our positivity rate are good ways to prevent that from happening. It does happen. I'd like to say that it never happens, but unfortunately, we're dealing with a very highly complex process, with very minute materials. So, labs do everything that they can. There're always ways to improve and we're always looking at, you know, things that we can do to keep things like this from happening. I will say that the testing laboratory has been very forthcoming and certainly doing all the things that they can to improve this process and to keep anything like this from happening again.

QUESTION: Dr. Sills, what's the takeaway from this, from the League and the teams, you think, how this would be handled if this happened, on say late in the week during the season, before a weekend of games?

Sills: I think, as we said, this is a great learning opportunity for us and I think we go back, together with the Players Association, with our committees of experts and we look at how our timing … What is the timing of our tests relative to the leadup of gameday? Which is, again, what we want to do is make sure we have the most accurate and timely testing information available. So, I think that is certainly a component we're looking at in great detail and again, we'll look at together with the Players Association.

We've made some adjustments already with the lab company as to how they verify tests before they're reported out. You know that we've already started using the point-of-care machines as part of our confirmatory process and so we're looking back at the data that we have on what our results have been with those and the concordance of those machines, again with the PCR test.

So, we need to put all that together and think about what is the safest possible protocol because again, our number-one goal is to keep everyone safe and make sure that as best we can no one steps onto the field on a Sunday or other gameday that is infected -whether that be player, coach, staff or other personnel.

I think also from this, in terms of the gameday, what we've learned and took away, is again that important piece of contact tracing and closed contact. All of these clubs that have these positive tests, immediately had to go to their contact tracing data and look and see who would be considered a close contact and there's an opportunity for clubs to do that on a proactive basis to take that information day by day to make sure they're doing the best possible job with distancing. So if they did have a positive test or multiple positive tests, that there would hopefully be, no close contact to those individuals as a result of how we're conducting our day to day business.

QUESTION: I know you got asked about this a little bit last week on the call, but I know in kind of the wake of what happened this weekend, there are a lot more questions at least that we've fielded about the status of saliva testing, especially similar to what the NBA might do. How close are you now, I guess since a few days since the last time we spoke, to having saliva tests and what do you guys believe the benefit would be once that sort of testing is available?

Sills: Well, I think again, as we said we're actively reviewing saliva testing and all other testing improvements, but anything that we want to adopt, we have to feel is a step forward in terms of accuracy and efficiency for testing. And, the steps that Patti described to you earlier, about how can contaminations can occur in the lab, those can happen whether the source of the material is saliva or nasal swab or a cheek swab or a throat swab and they're really independent of the source of the material. So, I think that, you know, when people think about saliva testing, it's not that the inning of itself is more accurate or it's easier to process. It's really just another source of the genetic material. So, for us, it's a matter of looking at what is the most, as I said, accurate and efficient type of test and we will continue to improve on that. As I said, I do believe test methodology and test availability will continue to change over the six months of our season, so I think you will see us likely making improvements along the way. But that is something that I think we have to realize, you know, saliva testing alone would not necessarily allow us to avoid the events of this weekend.

This is more about what happens in a laboratory and the fact that, as Patti said, these are really complex tests that involve multiple steps and tiny, tiny amounts of genetic information that we're looking to detect because when you do surveillance testing, which is what we're doing, which means you're testing large numbers of people who are asymptomatic, right? Remember, that if you're symptomatic, that puts you out of our protocol and into a whole different arm altogether. We're looking at testing, as I said to you, thousands of people daily who are asymptomatic, you're expecting very low prevalence and very low amounts of this genetic material. And so, the fact that such small amounts are present means that these are difficult and challenging essays to run and that's independent whether the source material was saliva, nasal swab or any other type of body source.

QUESTION: Could you provide some more specifics on how exactly these tests were contaminated? I know you mentioned some examples of how it can happen, but you haven't narrowed down or pinned down to us what exactly happened in this particular case?

Sills: I think, as Patti said, our testing partner believed that this happened in what's called the pre-analytical stage, which means after the test left the clubs and they arrived at this lab, but before they were put into the machine that's called the analyzer. So, if you think through the steps, the lab is getting in a number of these swabs that have a q-tip type swab sticking in them, a medium, a test tube of material. There has to be a transfer of some of that material from those individual samples into another type of test tube, if you will, to get them to run on the machine. And, Patti, forgive me, I know I'm giving a crazy explanation of that, but it's in that stage that there's a transfer of material from the original source to the analyzer, where this contamination occurred. And, that's what she was describing that occurs under a hood and involves, again, a lot of really delicate handling of very, very small amounts of material. Patti, you probably can do a much better job than I am explaining or expanding on that.

Walton: That actually sounded great. So, the transfer can be from the person that's working under the hood, it could be from their hand, their glove. It could be from actually the base of the hood or the size of the hood, the glass. So, that's the reason that we have very robust cleaning programs for our hoods and cleaning, making sure that we're cleaning before and after we process a run underneath the hood. The lab partner is pretty sure that the contamination actually happened underneath the hood.

QUESTION: So, the question is when it comes to the League's position, if there is one, does it have one, on fan attendance because there are circumstances where we know you've got protocols that limit, right now in camp personnel, team personnel only and very limited media access and all that. Very careful about that with the protocols. There are cases we know right now that teams are planning to invite in literally thousands of people and some none and I do know governments are involved in this as well, but does the League have some sort of position? Just given the careful nature of what you've been doing to try to prevent and limit the amount of others being around the team, rather than just having team personnel, players and personnel only involved in gameday. One thing to add here, what prompts this is Sean McDermott, head coach of the Bills calls it 'ridiculous' that from a competitive standpoint it seems to be an uneven playing field where the Dolphins for instance in week two will have fans for the Bills game and as of right now New York state is no fans for the Bills' September 13 opener.

Jeff Miller: Decisions made about fans in attendance are done in the first instance by state and local health authorities who make the determination as to whether or not it's permissible for any number of fans, or none, to congregate in the stadium, and we've abided by all of those state and local public health guidelines and have worked closely with those officials. Our clubs have worked closely with those officials in every state to understand what the parameters are.

That's what's going to lead us going forward too. As the situation evolves over the next weeks and months well continue to stay in touch with these officials who obviously, as we do, put the health of the communities first, and abide by their declarations. We're doing that in all of the states and all of the communities where our teams are playing.

So, the question you asked really goes back to the point that you made, which is to say is a determination of how many fans, if any, are permissible in the state and local communities where our teams are playing.

Sills: I was just going to add one thing to that and say it's not a surprise that there is regional variability in the state, because obviously there are differences in the state of the pandemic and the state of the infection as you move across the country. So, the fact that there's not a one-size-fits-all approach I think shouldn't be surprising given the medical situations across the league.

Miller: Let me just add one point. In the cities where fans can attend the games, there are thorough educational materials around social distancing, around masking, around other PPE and guidelines for those who are going to attend the games to ensure that we are following the best public health guidelines, whether they're state and local, whether they're formulated by the CDC. The public health guidance doesn't stop with the 'yes' or 'no' determination, it continues on for those fans who will be in attendance.

QUESTION: I know there's a lot of discussion between the league and the players union about frequency of testing. You guys settled on daily testing for now and I guess through September 5th. I'm wondering how much you think the fact that daily testing has contributed to your good results and what the likelihood is that gets extended beyond September 5th?

Sills: Those are still very active and ongoing conversations based around what the data is showing. As I highlighted to you, we're getting back week by week large chunks of information to help us better understand what's happening in our team environment, and so I think we and the Players Association want to continue to look at that and determine what seems to make the most sense to keep our team environment as save as possible.

I want to go back and reiterate something that I know many of you have heard me say several times. We know that testing, while it's important, is not the only important factor here because testing doesn't ultimately keep us safe. What keeps us safe are all of the factors that go into our team environment such as not showing up if you're sick and reporting your symptoms, wearing PPE, hand hygiene, the distancing that we're doing all throughout our team's facilities. All of those things go into it. Whether we test daily or three times a week or three times a day, those other factors have to be in place or else we're not going to be completely safe, as we know that these tests are not completely infallible.

QUESTION: Dr. Sills, it's actually a three-part question here so, what is the current thinking between the league and the players association on the in-season testing cadence? How close to kick-off realistically could you do the "pregame test" and still have time to weed out false positives like we saw over the weekend and is there any chance of using a point-of-care test on gameday?

Sills: So, as I said we are comprehensively looking at the pre-game testing cadence as far as when to test and exactly what test methodology to use because as you pointed out, what we want to make sure is we get the most up-to-date and current information but we also want to make sure that it's the most accurate information and as you've learned through this episode this weekend, it does take time to confirm some of these test results and if there is either a lab error or if there is an unconfirmed positive we have to run a few confirmatory steps.

That is a very active discussion that we are continuing to have with the Players Association, and by the way, with our medical advisers because again, we take this data and we take what we've learned and we look at it and in light of what everyone else is learning and we try to make what we think is going to be the safest possible decision. I do think we're actively looking at the role of the point-of-care machine, as I said, we're getting much more data about using them and how those results track with the PCR test, but we also need to make sure we are using more than one point, which is, some people have asked the question, well why don't you just use point of care for all of your tests?

I think the answer there is for several reason. One is, the supply chain of reagents for those tests is not as robust, so we would not be able to do the tens of thousands of tests that we're describing for you with point of care alone. There're also some deficiencies in the time it takes to run them which would come in to play. And then again, up until now, historically the point of care test has had a different accuracy profile compared to the PCR.

So, we have to factor all of those points in when we say what's the appropriate role of point of care. We exactly have the goals that I stated, which is get everyone on the field to make sure that they are not infected, and in doing so it does encompass when we test and what test we use, and what steps we take to be able to confirm those should they turn positive.

QUESTION: Dr. Sills, just a couple of question here on the procedures. Can you tell me how many labs actually handle just the NFL testing, and also, if those labs are all exclusive as to whether or not these labs are also conducting tests for none-NFL situations?

Sills: As far as the lab question – we have one national lab testing partner, the company that we're using. They do have five different laboratories I believe that process our samples, and they are not exclusive to NFL work, meaning that this company does do work with some other professional sports leagues, as well as some non-sports related work.

What they've set up for us is sort of a separate division, if you will, that handles all of the collections, logistics, transport and reporting of our samples so that it's in effect almost a separate stream of work for them. Those laboratories do also have other work as I stated a moment ago.

QUESTION: So, when you think about the contamination is it fair to assume that maybe the contamination occurred because of the fact that there are non-NFL tests going on as well at that same lab or would that be a bit uncertain?

Sills: No, that's something that we have to continue to investigate and our lab partners are investigating. I think I spoke to you earlier at the start of the call about the incredible low rates that we've seen of positive tests. I would never say that some of that material couldn't come from one of our tests, but certainly if the lab is handling other samples it could very well be that source.

What's important going forward – I don't know that we'll ever be able to answer that exact question for this episode – what's important going forward are all of the things that Patti mentioned, which are, what are additional steps that can be taken to help minimize the risk of that.

Let's put this into context, this was an incredibly rare event. Our lab partner now just through the first four weeks of our program has run almost 200,000 tests and we're talking about 77 samples here. Now, we all want that number to be zero, but it's a tiny fraction of the overall number of tests that have been done and I think it speaks to the fact that overall, our testing program has worked extremely well.

Most importantly, to me the most important thing is we got through four weeks thus far without any of our clubs having a major outbreak. Certainly, it's far too early to celebrate that, but I do think that we should acknowledge that our clubs have done a terrific job – players, coaches, staff – of following our protocols and I think our protocols are working. I think we've shown that they're having the results that we want, and the events of this weekend shouldn't change that view.

# # #