Transcript of Briefing by NFL Chief Medical Officer Dr. Allen Sills on COVID-19 Testing

The NFL hosted a call with members of the media on August 12, 2020 to discuss initial results of COVID-19 testing as 2020 training camps opened. 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:


As a precondition to entering training camp, intake testing was done on all players and personnel.

-- 9,983 players and personnel tested

  • New positives: 170 players and personnel, or 1.7 percent
  • Of that group, 2,840 were players

-- New positives: 53 players, or 1.9 percent


Players and personnel continue to be tested on an ongoing basis as practices and camps continue.

-- Through August 11, 109,075 total tests completed among players and personnel (includes intake testing)

  • All players and personnel: Positivity rate of 0.46 percent
  • Players: Positivity rate of 0.81 percent

-- The overall positivity rate has not exceeded 1.7 percent for any club since testing began.

*Speaker: *

  • Dr. Allen Sills, NFL Chief Medical Officer


Dr. Allen Sills: Good afternoon, everybody. Pleased to give you some updates this afternoon about our testing program and specifically some of our initial experience and how that informs some of our decisions about going forward.

So, I think you're all aware that we had a four-day intake process for all of our players, coaches, and staff, all of our personnel, meaning that they underwent three tests done over four different days. We did that very deliberately based on, again, experience from other sports and what we've seen with experience of other leagues around the world to try to reduce, obviously, the risk of anyone coming in and infecting a team environment. I think it's also important to realize that when you look at entry testing, intake testing, you're obviously not learning anything about the team environment because you haven't even been together. You're just seeing what is everyone bringing in from their own experiences. And then, obviously, in this case, we had players, coaches, and staff coming from around the country and even around the world.

So, I do have some numbers that I can give to you and share with you on that and I'll do in a moment. The other thing I think we'd like to talk about is a little bit about the decision about testing going forward. I think everyone is aware that our protocol has stated, our agreement with the NFL Players Association, that we would do daily testing for the first 14 days and that we would then look at the positivity rates, and if those were below 5 percent, then we would transition to every other day testing. I think some of you are probably aware that we have reached a decision together with the Players Association to continue daily testing until further notice. And I wanted to talk a little bit about that decision and why we made that decision, as well as how it relates to the data that we've been gathering.

So, let me talk through each of those sequentially. First of all, on the intake, we tested 9,983 people – players, coaches, other staff – upon their intake. New positives, meaning people without a known history of COVID infection leading up to that intake were 170 people, so that's 1.7 percent. The total number of players tested out of that group was 2,840 and the total number of players that were new positives, meaning again, no history of COVID infection leading up to that intake, was 53, which I believe computes to 1.9 percent.

So, that again is a snapshot of what we found when everyone came together for that intake. Again, you know that the rookies came in first, the veterans subsequent to that, and then the coaches and staff came in at the time of the rookies. So, that reflects that snapshot and what we were dealing with when we came in. I think it's important to recognize that in those positive case numbers that I just gave you, not every single one of those positive tests meant that that person was actively infected.

And I think we talked about this last week, one of the challenges of testing is interpreting the test results with the clinical results. So, people can test positive, obviously because they are actively infected, that's one reason. They can also test positive because they've been previously infected and they still have some viral debris around, or they can test positive if they just have viral remnants that they've touched on a surface or anything of that nature. So, a positive test does not mean a new COVID infection, but the number that I'm giving you is the total number of positive tests that we had at that intake.

Since that time, with the monitoring phase, we've done through yesterday, through August 11, we've done 109,075 COVID tests. Again, players, coaches, and staff. The overall positivity rate for those tests has been 0.46 percent, or less than half of a percent, and the overall positivity rate if we look at players alone is 0.81 percent, so, again, less than one percent.

And we've also looked at that positivity rate not just for the league as a whole, but we've looked at it on a club-by-club basis. We've looked at each club and we've looked at that each day and the overall test positivity rate has not exceeded 1.7 percent for any club since we started testing.

So, I think I mentioned early on in the first part of my remarks that as you're aware, our protocol said if the positive test rate is less than 5 percent, we would go to every other day testing. We've agreed with the Players Association to continue daily testing. Why would we make that decision?

Well, I think there are a couple of important reasons. Number one, we did make a couple of changes to the protocol last week. We spoke about that, we talked about trying to confirm positive tests and doing that with a two-step process that we outlined last Friday. So, that was a substantial change to the protocol, and one of the other factors that was in part of that change was starting to use these point-of-care machines, which are the rapid antigen tests that are available on-site. We explained that that was part of our confirmatory process.

So, in addition to those two reasons, I think we've also recognized that we're constantly learning from the testing results and we've learned as I mentioned a minute ago, not every positive test reflects a new infection. In fact, we've categorized those positive results into persistent positives, meaning someone previously infected, unconfirmed positives, meaning an isolated positive surrounded by negative tests before and after, and then obviously those tests which reflect potential new infection.

So, I think the bottom line is we are continuing to learn a great deal from our testing results and I think that given the protocol changes that we recently made, as well as the use of this additional point-of-care technology, and the recognition that we are about to go into more of team-based activity during training camp, that we and the Players Association together felt that it was prudent to extend the daily testing until further notice.

So, that's an agreement that we reached with them today and we look forward, obviously, to continuing to track these rates and seeing what else we'll learn because I'm convinced we will continue to learn a great deal over the coming weeks with those test results.

Last thing I'll say, and then I'll stop for your questions is: Going forward we certainly want to continue to report our test data to you, but I think it's important to realize that we plan to release that data combined with the clinical outcomes. Because at the end of the day what we're really interested in is: how many new COVID infections are we detecting? That's really the measure of infection control that we're interested in. And so, as I mentioned earlier, just reporting a number of positive tests really doesn't give you that data piece because the total number of positive tests reflects those other conditions that we've already talked about. So, I think you can have an expectation going forward that we will release on a regular cadence the clinical data referable to any of these new infections that I mentioned.

I'll stop there, and we can do some questions.

QUESTION: Two-part question. First part, when you did the intake testing and then you mention the 109,075 tests, is that 109,075 tests since the intake or does that include the intake?

And then the second part of it is, when we're talking about the positivity rates, the new cases, do you have that broken down in terms of symptomatic or not, whether anyone has been hospitalized, etc.?

Sills: That number, 109,000, does include that intake, and then the second part — I think you're asking about the positive cases during the monitoring phase, is that correct, that was your question?

QUESTION: The overall, you know, outcomes of whether or not there have been, there are some guys who have been on the reserve COVID list for over two weeks now and I'm wondering: Do we have a breakdown in terms of how many of the positives were actually symptomatic, whether anybody had serious medical outcomes or not?

Sills: Yeah, right, I understand your question now. We are still gathering that data about the clinical outcomes because again we're trying not only to monitor: were they symptomatic or not?, but we're trying to determine would they fall into that bucket of persistent positives or unconfirmed positives. So, as you can imagine with 109,000 tests, there's a lot of data quality and data cleaning that we want to do to make sure we get accurate numbers from that, and as I said, that number includes tests that we did up until yesterday. So we've got a little bit more work to do to define that cohort. I think we will have that number for you. I'm not aware of anyone that has had what I would call "severe illness" up until this point.

QUESTION: This isn't specifically related to testing but obviously it's something that's been very much in the news related to college football. I was hoping you could take us through a little bit more about what the extra cardiac screening is that's in the protocol: what players who had previously tested positive or had the antibodies, positive antibody test, are going through, and maybe share a little bit more with us about what you have learned from that screening and how much of a concern that is for you guys at the league level.

Sills: We've certainly been aware of the potential for cardiac complications ever since we began putting the protocols together. We had a group that has been advising us on that, a group of sports cardiologists; they've learned and looked at the data that has emerged over the intervening months since the pandemic began.

So, it is written into our protocols, as you mentioned, that anyone with a known previous COVID infection or that presents with a new obvious infection, that those individuals should undergo, at a minimum, a 12-lead EKG, troponin levels — which are blood tests for heart function — as well as an echocardiogram. There's the option to do additional screening tests at the discretion of the team physician, and then there's a recommendation again, if those players have been a documented positive case, that they undergo a graded exertion protocol, again, under the direction of the team physician.

So, that is written into our protocols, and I thinks it's something as I said, that has been on the minds of our team physicians throughout.

And, it's on the minds of our players. So, I think there are important and ongoing conversations when players have tested positive about what those screening tests mean and what's the best way to rule out any of those complications. So, it is something we'll continue to monitor and I think one of the opportunities that we will have will be to contribute our data as we've done all these evaluations and look at that group as a whole and see what we've learned and what the outcomes have showed us. Because that's obviously an important issue right now for all of the sports medicine world.

QUESTION: Just to follow up on the question about the myocarditis, if I pronounced that properly, of the 109,000 tests done, there has been no team player or personnel who has indicated any type of heart issue like that?

Sills: I don't have all the outcomes of the cardiac data. I wasn't prepared to bring that to you today, so we'll have to get back to give you any more color on that. Again, I think all of you are aware that there's been at least one player that publicly has been identified that they detected a cardiac abnormality not related to COVID as a result of cardiac screening that was done as part of our protocol, so certainly there have been some things that have been identified, but to your point of which of those are COVID-related, I think those are things that we're still sorting through very much, and we'll have to get back to you on that.

QUESTION: And just to quickly follow up that, is there a lot of data on viruses, coronaviruses in general, and that heart issue in particular as far as any that we can go by for percentages or likelihoods in your deliberations about how safe it is to proceed?

Sills: Well, I think all of us in medicine have known for a long time that you can have cardiac complications after viral illnesses and after even bacterial illnesses, there are a number of conditions that can have cardiac complications, so that's not a new phenomenon in medicine. I think what's unclear at this point is what's the prevalence of those changes after COVID-19 infection and how might it relate to either severity or duration of illness.

So, those are questions that are still unknown to the medical community at large, and that's why again I think we in the NFL will have an important opportunity to contribute what we're finding to the world's body of knowledge there as they continue to explore that issue.

QUESTION: What's the status of gameday protocols for a number of positive tests that could happen, say, before a game? I don't want to use the word outbreak, but if there are several tests or positives within a position group, things like that.

Sills: Well, we're still finalizing some aspects of the gameday protocols, and so we'll obviously be releasing those and have some updates with regard to that, but I think that, again, when you look at interpreting the data, one of the things that we do is, we're looking on a day by day basis.

Again, these testing results and the screening results and the clinical reporting, it happens on a day by day basis, and that's being monitored not only by us at the league, but at the NFL Players Association, their medical advisors, and our infectious disease consultants and advisors, and so we're watching not just about gameday, but throughout and trying to see: are we meeting our standards for safety in our facilities?

As we approach gameday, certainly, again, we will have a very specific protocol in place about what testing and reporting looks like, but I think it's hard to make exact number cutoffs in terms of what an algorithm would point you in one direction or the other. What we have to look at obviously – again, I illustrate that with the positive test dilemma that I showed you today, for example – if you just said, well, this many positive tests, you really have to dig into that and say, how many of those positive tests represent really new infections, or are those positive tests persistent, or are they unconfirmed; so, delineating that takes some clinical judgement, which we have to use in conjunction with those protocols.

So, our goal is all the same, to have the safest possible environment for everyone. We want to try to ensure that there's no one – player, coach, staff member, official, anyone – who steps onto a field with an active COVID infection. That's our goal. And everything that we build in the protocol will be based around that premise of how we do all that we can to ensure that no one steps on the field who is actively infected.

QUESTION: Do you guys have any numbers on how many players have gotten coronavirus since the start of the pandemic, even from before arriving at camp? Do you know that number yet?

Sills: We can get you the number, I don't have it in front of me here, of how many have reported a positive test. The other challenge with that is: we certainly know that there were some people who did not have a known positive test but tested positive for antibodies, which suggested they had in fact been infected or exposed, and then there were other individuals who came in who basically had every symptom in the book of the coronavirus infection, but they never got tested, so clinically they would have met the diagnosis, but they didn't have a test that documented that.

So, that's what makes those determinations a little bit difficult, but we know that there are some that are in those two categories I just mentioned because they're some of the people who had what I would call an unconfirmed positive test after arrival, which most likely reflects the fact that they did have a previous infection or exposure before they came in.

QUESTION: Just wanted to double check, did you say 109,000 tests that the NFL has conducted so far?

Sills: Yes, 109,075.

QUESTION: There have been a handful of players who have been on the list for more than two weeks, 15+ days. Have there been any serious cases of COVID among the players?

Sills: Again, I think when you talk about serious illness, people may define that differently, but I'm not aware of anyone that's been seriously ill to this point. I think you have to, again, recognize that people go on and off those lists for a variety of reasons. Sometimes it's because they have an active infection. Sometimes it's because they're a close contact, or they're being quarantined, perhaps they have a household member who's actively infected and someone's being extra cautious. So, there are a variety of reasons why someone may appear on those lists. I think the other thing to recognize, as I said before, is that returning from an active infection means not just clearing your symptoms, but it also means going through any additional screening as we talked about, as well as this graded exertion protocol in taking a go slow approach, so in that sense, people's illness journey may be very different, and you may see varying amounts of time in terms of recovery, and so, again, I think that's why you'll see some variability in perhaps duration on those lists.

QUESTION: Are you able to delineate or separate how many people have tested positive since the intake process; in other words, since they got clearance into the team facility, how many have tested positive since then? Or is that one of the positivity rates you quoted earlier?

Sills: Well, the positivity rates that I quoted to you is reflective of that total number of positives that we have. I have a total number, but, what we're trying to do is separate that number out, as I mentioned before. We think we'd like to stop reporting just positive tests and start talking about persistent positives versus unconfirmed versus these potential new infections because that is what's much more meaningful, right?

You know, what you really want to detect is your testing program. What you're really looking to find are people who may be newly infected. That's the whole point of having our surveillance program, so I think you understand how it gets complicated very quickly when you're trying to sort out who's truly a new infection from those other conditions that I mentioned, but it's the new infections that are the ones that are the obvious trigger. You still have to go through contact tracing, isolation, etc., for everybody, but once you confirm it's a positive, then those are obviously the people that you are most concerned they represent those new infections.

So, I think as we look to report that data to you going forward, we think it's important to segregate it out, and we just haven't completed that – as I said, I've given you the data up through yesterday. It takes a little bit of time to go back and match clinical outcomes, symptoms, and all of that with those positive tests. So, we will have that. I just didn't have that for you today, and that's why I said I just gave you the overall positivity rate.

When I say those positivity rates that I gave you, that includes not just these new infections, but people who may be persistent positive or unconfirmed positive, so what that shows us is that we never even got anywhere near that 5 percent threshold, even if we include people who we know are persistent positives or unconfirmed positives. So, to that point, undoubtedly our total number of those new infection positives is going to be even quite a bit lower than those percentages that I gave you.

QUESTION: So, do you view that as a positive in terms of how the protocols are working, or is that simply that people prior to coming to training camp had kept themselves clear?

Sills: I think it's both, because, again, the intake numbers I think we were pleasantly surprised at how few positive tests we had, and I think since that time that positivity rate that I gave you reflects the fact that our teams, players, staff, and coaches have done a terrific job of staying uninfected, so I do think it's both. I think the two different bits of data I gave you point to each one of those conclusions: the intake data suggests just what you've said, that when people came in, there really were, in my view, a relatively low number of positive tests, and since that time, our positivity rate, even given all the caveats I gave you, suggests that we've been doing a really good job of keeping out new infections.

QUESTION: Did you have an expectation going into, before testing, of what you thought the initial numbers would be?

Sills: If I've learned anything through this pandemic it's to not make predictions. So, I don't know that I had a number in mind. I just think that given the fact that as our clubs were coming together and the fact that we had players coming together from a large number of hotspots at that time, I would not have been surprised if the numbers had been substantially higher. So, as I said before, I was pleasantly surprised at the low numbers on intake.

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