Can Sports Return Without Setting off a COVID-19 "Biological Bomb?"

Emory University epidemiologist Zach Binney on MLB's Arizona plan, UFC's fight island, and the challenges of restarting sports during the coronavirus pandemic

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Local media dubbed it “Game Zero.” One doctor called it a “biological bomb.” On February 19, a Champions League soccer match held in Milan between Atalanta, an Italian team from nearby Bergamo, and Valencia, a Spanish team, drew over 40,000 fans from both countries.

Weeks later, players from both teams had tested positive for coronavirus, while the Spanish region of Valencia and the Italian province of Bergamo had become COVID-19 epicenters with nearly 10,000 confirmed cases between them.

Moreover, Bergamo held the tragic distinction as the most deadly province in all of Italy for the pandemic, with more than 1,000 deaths from the virus.

Though it’s impossible to know exactly what role the match played in spreading the virus within Bergamo and to other parts of Italy—as well as Spain—this much is certain: one week after the match, the first coronavirus cases were reported in Bergamo.

Meanwhile, a journalist who traveled to the match became the second person infected in Valencia, followed by people who were in contact with him and fans who also had gone to the match.

“I’m sure that 40,000 people hugging and kissing each other while standing a centimeter apart—four times, because Atalanta scored four goals [in the match]— was definitely a huge accelerator for contagion,” Luca Lorini, the head of the intensive care unit at a Bergamo hospital, later told The Associated Press.

To comply with government-issued public health guidelines aimed at limiting COVID-19’s spread and preventing a similar situation, American professional and college sports have gone on hiatus. Some—including the National Basketball Association, the National Hockey League, Major League Baseball, and the Ultimate Fighting Championship—have discussed or floated plans to resume play under limited, quarantine-like conditions.

But when can sports responsibly resume? And under what circumstances would that make practical and medical sense, both inside and outside stadiums, ballparks, and arenas?

To get a better sense of the COVID-19 challenges facing leagues and organizations and the possible effectiveness of proposed workarounds, Hreal Sports spoke to Zach Binney, an epidemiologist at Emory University who wrote his dissertation on injuries in the National Football League.

(The following conversation has been lightly edited for brevity and clarity).

Hreal Sports: Let’s start with a soccer match in Italy. The now-infamous Champions League match that took place in Milan on Feb. 19 between Atalanta, an Italian team, and Valencia, a Spanish team, and since has been identified as a likely super-spreader event for the coronavirus, with 40,000-plus fans exposing themselves to infection and helping carry it back to other parts of Spain and Italy. There’s a famous quote from an Italian doctor calling it a “biological bomb.”

If we were to re-open sports here in the United States right now or soon, to what extent would we be risking the same kind of outcome?

Zach Binney: That's a really good question. Let me step back by talking more generally about infectious disease transmission. Basically, every person you add to a gathering increases the risk of spreading a disease in two ways.

One, every person you add to a gathering is another person who could be sick with COVID-19. The second way is that every person you add to a gathering is somebody else who if they're not infected, could become infected. 

So, the absolute safest way that you can exist is as a single, isolated person in your home—because then, there's nobody who can transmit the virus to you. 

Two people is slightly more dangerous than one. Ten is more dangerous than two. Fifty is more dangerous than 10. Five hundred is more dangerous than 50. Fifty thousand, 70,000, 100,000 in college football, that would be an enormous increase in risk. The bigger the event, the greater the risk for just “normal” spread or to have a super-spreading kind of event. 

And that risk would also increase if you have an event that's taking people in from really broad geographical areas. One important thing to understand about the epidemic right now—and I think there's a lot of misconceptions about this—is we don't have one epidemic in the United States. We have a whole bunch of localized epidemics at various stages.

Places like Washington and California, they acted really early. And they seem to have flattened the curve pretty successfully. And so they haven't had as big outbreaks as other areas. In New York City, the current data seems to show that they are at or near their peak in hospitalizations, and hopefully, eventually, those will start to go down —as long as they maintain current social distancing regulations.

Then you have other areas that are still thought to be on the upswing. And it's kind of hard to know—because we still don't have the testing we need in those areas—exactly where we are in the curve. But all of that is to say that if you have a sporting event that brings people in from multiple areas of the country, that could add a little bit more risk. Because what if you get someone from an area that's hotter than the local area?

Even if you were trying to host something in, I don't know, Seattle, and there wasn't a lot of person-to-person transmission, if you have people flying into that event from New York, or Miami, or somewhere where there's more transmission, then then that's a greater risk as well. 

Is there anything about the nature of sporting events—how close people sit together, how they go to bars and restaurants together before and after games—that makes them more risky or risky in a different way than other types of gatherings or events?

It depends on the particular event. We know that transmission is of respiratory illnesses is generally easier indoors than outdoors. Again, the more people you have, the higher risk it is. And the closer they are packed together, whether that be in a sports stadium or in a crowded nightclub, that would certainly increase the risk.  

We ask people to stay at least six feet apart when they venture out of their homes. So any environment in which you can't do that, there's added risk. There certainly are a lot of opportunities in a sporting arena to be in close contact with a lot of people—waiting to get in, going to the exits, in line for beer or concessions, in the bathrooms, packed into the stands—that maybe there aren't as many opportunities for if you went to, say, a restaurant that was operating at half-capacity. 

Something like that would probably be easier to bring back than sports with fans in the stands.

Let’s talk about proposals for quarantined sports events and leagues—essentially, the “biodome” set of proposals. We’ve seen the UFC talk about a “fight island,” the NBA consider some sort of reduced version of itself in Las Vegas, the NHL’s vague discussion about playing in North Dakota. Then, of course, there was the big MLB “Arizona” plan where you’d pretty much heave the entire league somehow operating in and around Phoenix.

The basic idea, I guess, is that everyone involved—athletes, officials, team staff, even the cleaning crews for the stadiums—would live in some kind of isolated bubble. What sort of structure would have to be put into place, and what sort of steps would need to be followed, to make this work?

All of these ideas can seem simple in theory. But when you start drilling down on how exactly it would be done, you discover a lot of complexities—and while all of these plans share the same complexities and challenges, those do get bigger as you increase scale of the event.

So, how would you theoretically do a full biodome for, say, the NBA? Everybody who would have any contact with anybody involved in a NBA game—or who would be involved in keeping those players alive, and fed, and in clean conditions, and things like that—you would have to isolate them completely, including from their families.

You’d then want to wait about five to seven days, and then give them a COVID-19 test. If that test is negative, you'd probably still want to isolate them for another week or so to give them a chance to test positive at the end of a full 14-day period. 

So then you give them another test. They test negative. Great! Now you have to transfer them as quickly and sterilely as possible into the quarantine zone, where you're trying to maintain a completely virus-free system. So you would have to do that for players, officials, coaches, medical staff, any broadcast staff or media—and potentially, if you’re housing these folks in hotels, then any of the cleaning staff, food preparation staff, all of that. Oh, and then you would have to have a security staff. And then you would have to allow nobody else to enter that system. And any supplies that entered that system would have to be thoroughly disinfected. So any food deliveries or anything like that.

If you were able to do that and expend the economic resources and overcome the logistical challenges inherent in that, then there's nothing to say that's impossible. It's just going to be very, very difficult. And, it will require redirecting resources, medical sources, COVID-19 testing resources, from other areas. And we really should be at a point where that's not a problem before we start doing that—otherwise that becomes really ethically questionable if we're taking away tests that could be used for sick patients or for physicians. Or if we’re taking away physicians, or nurses, or even athletic trainers who could be helping staff the larger medical system during an outbreak.

This all seems extreme.

How extreme you have to go depends on the situation on the ground at the time that you're trying to bring the sport back. And the main thing here is, how much community based person to person transmission is there? 

Right now, we don't know how much there is. But we do know that it's a lot. And that creates a situation where you really probably would want to do something like a full biodome in order to minimize the risk that the virus gets into the league that's trying to play. 

If you have a situation where we maintain social distancing, and shelter in place, and we are able to get new cases down to a trickle—at least in most areas—then the baseline risk of having an infected person get into a game or a training facility or something like that goes down. So you could get the overall risk of a COVID-19 case down to a level that's near enough to zero that maybe it’s sort of a softer, non-biodome quarantine—maybe something like having all the team and league officials sequestered in a hotel, but maybe the hotel workers can go home and just be tested every couple of days. You still test everybody affiliated with teams and leagues every couple of days, and anybody who tests positive would be held out immediately and isolated for 14 days. Maybe could you do it that way.


Right. I want to get back to that scenario, because it sounds similar to what it actually happening right now in Taiwan. But let’s go back to the biodome idea. What are the problems with it in terms of the expense and effort, and what are some of the things that could go wrong?

The major challenges would be finding an area with enough facilities to house and train teams, have locker rooms, have courts or fields, and so on. We’ve seen leaks coming up with some solutions for that

Then you’d have the problem of the sheer number of people that you would need to isolate—and isolate on a volunteer basis, or else you need to have really strict security to make sure that they have had zero or near-zero chance of becoming infected with a virus for two weeks. 

Those people would need to be tested. And the number of tests you would need to run would not be a small number. You also would need to find hotels that are willing to house these players or another dormitory-type solution—with the economy as it is, maybe hotels would be willing to do that.

The players and everybody affiliated with the league would have to volunteer to be sequestered for weeks to months, with or without their families. I imagine many of them may not find that pleasant. So you'd have to negotiate with the union. Then there’s support staff. You'd have to find volunteers willing to do that. For some amount of pay, you would probably find people willing to step away from their families and serve in that kind of role, as housekeeping staff or food prep folks. Stuff like that. 

Oh, and then another challenge that comes up: what if somebody gets injured and has to go to a hospital? How is that dealt with? They'll certainly have to restart the isolation process all over again. 


There’s a problem anytime anybody needs to leave. What if someone’s wife has a kid? What if there’s a family emergency? What if their father or grandfather or sister is dying? In order to go see them, they have to commit to being away from the team for two weeks. That could be a challenge.

This seems enormously difficult. But let’s say everyone has good intentions and is really trying and wants to do this, and you find a bunch of people who are willing, and everything you just laid out, a sports league puts into place. What could still go wrong?

You could have a security lapse where somebody gets out. Maybe a player wants to get out for some reason. I don't want to speculate why! But if they're able to sneak past security, if it's not airtight, that's a possibility. 

Somebody could break through security, too, maybe a fan who wants to see somebody. You'd have to be really vigilant about that. You also could have a contaminated delivery package. I think as long as you were rigorously following disinfection protocols, there’s probably pretty low risk of that being the way that the virus gets into the system. 

Transportation between facilities always provides chances for infection, especially if you have a system where you are traveling between cities—with that, you would also need to have a plane and the staff for the plane that is known to be virus-free. And, you know, how do you how do you manage that? 

So basically any person getting in or out—and any way that the virus gets in on an object, like a package—or any lapses in the quarantine during transportation, all of those are risks.

It sounds like all of these challenges scale up with the size of the event or particular sport or league that you’re trying to restart. Would it be a lot more doable to try a biodome approach on a smaller scale—like a one-off fight or a small, one-off tournament—than something like MLB’s proposal to play some sort of season with all of its teams?

It does seem doable on a much smaller scale. So maybe something like the UFC fight island would be a little more plausible than a full-on baseball season. Sports which involve more people, which are more complex, and have longer seasons, all of that requires bigger sacrifices from everybody involved.

But the challenges in creating a closed virus free system are essentially the same. So I think it it moves from difficult to really difficult pretty quickly. Even the UFC, if they want it to do it really airtight, it would take at least two weeks—because that's how long it would take to be sure that somebody is free of the virus before they can be moved to the quarantine area where they're trying to hold their event.

None of this can be done in an airtight way over a weekend. So you'd still have to make that upfront investment. So you'd have to decide: is that worth it for one UFC pay-per-view? Maybe it is. Maybe it isn't. I don't know.

The WWE has been holding and taping matches without fans in empty, controlled environments. And it was just reported that that one of its employees recently tested positive for coronavirus. According to the WWE, the unnamed employee and a roommate showed symptoms of the virus after having dinner with two health-care workers on March 26. What does that tell us about the difficulty of pulling off the biodome scenario?

People going to dinner with their friends who work in healthcare is probably not a good idea right now—healthcare workers are in a really high risk group! And they don't want to risk spreading the virus to you any more than then you want to catch it from them.

Now, I don't know what this person who became infected was told to do or not do. I don't want to speculate on what WWE was saying to its people, because I have no idea. 

However, I was certainly concerned with what they were continuing to do with the safeguards which they had in place. The ones that have been publicly reported strike me as insufficient.

[Editor’s note: In addition to relocating its show tapings to a WWE facility in Orlando, the company reportedly is limiting the number of staffers on hand, forbidding access to anyone who has traveled outside of the United States or come into contact with someone who has, asking performers to not travel outside of the Orlando area during taping periods, and checking the temperatures of everyone who comes into the facility].

They don't let anybody into the facility if they have a fever? Well, not everybody with COVID-19 gets a fever. And we know a large proportion of people can still transmit the virus even if they have no symptoms at all. 

It’s good that they are doing it without fans—again, every time you add a person to an event, it makes it more dangerous. But there's still danger in any gatherings right now. And as far as I know, they don't have, like, wrestler isolation camp where all these performers are going when they’re not taping stuff. My understanding is that for WrestleMania, at least, they were flying wrestlers in from around the country, and that they weren’t quarantined or isolated in any way. I wouldn’t be surprised to find out that they hadn’t all been tested, because we simply don’t have the capacity for that right now.

Let’s move on to a second way of restarting sports. It’s a more relaxed version of the biodome—something we are seeing in Taiwan right now, where they are still playing basketball and just started playing baseball and soccer under unusual conditions: five teams in a single small gym with no more than 100 occupants for the Super Basketball League, and empty stadiums with cardboard cutouts and robot fans for the Chinese Professional Baseball League and Taiwan Football Premier League.

From everything you’ve said, it doesn’t sound like it would be safe or responsible to do this in the US right now, given our current situation with the virus. What would the situation in this country have to be in order to make a Taiwanese approach possible?

The thing that people should understand about Taiwan is they had experience with a situation like COVID-19 back in 2003 with SARS. So this is one of the most prepared places on the planet. They were aggressive, they moved early, and they largely kept their epidemic under control.

When you say “under control,” what do you mean?

They kept the number of cases low. They did not get far into exponential growth—one person spreads it to three people, and then those three spread it to three others, so it becomes nine, then 27, and so on. They stopped the virus early in that process. Which means they could then identify and track and isolate new cases. 

[Editor’s note: as of April 12, Taiwan had reported 388 coronavirus cases and six deaths in a population of around 24 million].

With the number of new cases down to a trickle, their public health authorities are actually allowing gatherings of up to 500 people. So they are reaping the rewards of acting early and acting aggressively. The longer you wait—the more cases there are and the more transmission there is—the longer it takes to kind of get over that peak and get back down onto the other side.

Taiwan kept their curve very, very flat. We did not do that, at least not in certain areas of the country. We acted slower. We are now reaping what we sowed. And it will take us longe—months, at least—to get down to the point where Taiwan is.

If the US can get to that point and is able to restart sports under similar restrictions, what could still go wrong?

We've already seen some false starts with, for example, the Chinese Basketball Association.

[Editor’s note: the CBA, which has been on hold since Jan. 24, originally planned to restart on April 15 but is now postponing play until at least July, in part because the Chinese government has banned both large-scale sports gatherings and entry from non-citizens in order to contain the coronavirus].

There's always the chance for another wave of infection to break out if we lose vigilance. If people stop social distancing to the degree that public health authorities are asking for, if people are not willing to get tested, if they’re not willing to isolate if they test positive—these are all broader social concerns that can make the situation worse for everyone. And all of that could potentially force a stoppage. 

You could also just get unlucky. Even with low community-based transmission, you could have somebody on a team get sick. Depending on how much contact that person had between when they may have gotten infected and when they tested positive, maybe you would have to quarantine their whole team until you can be sure that they're not sick. On the other hand, if you were testing frequently and aggressively enough, and the tests weren't showing a false negative too often, then the risk of that virus becoming widespread might be relatively lot. It might be low enough that you could argue that it's okay to continue with games.

But there's always the possibility that the situation could get worse again.

So if we get to the point in America where we can do this—a league decides, “we’re gonna play, we’re going to take all these precautionary steps”—that league could still get that positive test or tests and end up having to stop its season for two weeks or longer. There are no guarantees you won’t be thrown right back into a big disruption. 

No plan is foolproof, especially when it comes to a virus like COVID-19. 

The broader thing to understand is that everything is a trade-off. It's not like the choices are biodome or nothing or soft quarantine or nothing. There are all of these decisions that you can make along a continuum, and every single one of them will have some economic cost if you do them and will add some viral risk if you don't. It will be incumbent on the leagues and their advisors—which will hopefully include public health officials and epidemiologists—to work together to decide on what makes the most risk-benefit sense for them. Public health, player health, and staff health always has to be the top concern.

Speaking of that: we just saw the UFC nix a planned event for April 18 that was going to be held on Native American tribal land. California state government officials and leadership at Disney and ESPN—the latter is UFC’s broadcast partner—reportedly pressured the company to cancel. So it seems like it won’t just be the leagues making these decisions—no pun intended—in a bubble. They’re going to have to work with governments, public health people, networks, even their corporate sponsors. Everyone is going to have to be on board and feel like whatever plan they are following falls within an acceptable level of risk.

That’s a fair assessment. Government officials, certainly in California, have expressed concerns about not holding sporting events with fans until there's a COVID-19 vaccine. I think that's probably a valid concern.

If you’re a league, you're always going to have sponsors and TV networks and other interested stakeholders trying to push you in one direction or another. And hopefully, they’ll have public health officials talking to them about the the risks that they would be taking on with various plans as well. And all of that's going to have to balance out—it's anybody's guess as to how it will all shake out.

I will say that I've actually been pleasantly surprised by the restraint and responsibility shown by most sports leagues—and certainly the Big Four—in how they're dealing with the COVID-19 pandemic. Everybody wants to put plans out there, and I don't necessarily have a problem floating them as trial balloons. That's not an inherently bad thing. Then you can get feedback. Sometimes the feedback is positive. And sometimes it's not so positive.

“Not so positive” might be an understatement!

Right. But from the NBA suspending its season as soon as it had its first positive test, to the NFL planing a completely virtual draft and really limiting physicals for free agency and things like that, to MLB and the NHL suspending their seasons, I’ve been really surprised with their actions and what they’ve actually done. I hope it continues.

Let’s go back to your notion of a continuum. One possible step toward normalcy—past even what we are seeing in Taiwan right now—would be to have some fans in the building, but not a full house. Over the weekend, a Morgan Stanley biotech analyst put out a report about how he thinks this pandemic will play out over time. And one of the things he wrote was that large venues like sports arenas, concert halls, and theme parks are “likely to remain shut or have attendance capped at 10 to 25 percent of prior levels.”

So could we have a situation where you have some fans back in buildings, but not too many? Similar to what you mentioned earlier about restaurants that don’t have too many people, that have sufficient distance between tables? And where would the country as a whole have to be with the pandemic to make that a reasonable thing to attempt?

There's value in getting sports back—but how much added value is there to having fans in attendance? I think that's the question people need to be asking, and balancing that against what the risk is of having even one fan in the stadium.

The risk is going to depend on how much person-to-person transmission there is in the area where the game is happening at the time—the less there is, the lower risk there is. But we are certainly not in a situation now—or, I would say, in the next few months—where it seems like we could have any fans in stadiums.

In fact, I'm pessimistic that we could do it before we have a vaccine. But you know, I'm a scientist. I always have to be open to being proven wrong. We could be totally wrong about some aspects of the outbreak.

But think of this: even if you're only at 10 or 25 percent capacity in the seats, even if you can maintain that six-foot distancing, how are you doing that in concession lines? How are you doing that in bathrooms? How are you doing that on the way out of the stadium in the parking lot? And how are you going to enforce that people stay six feet away from each other at all times?

My last question is about college sports. Theoretically, you could bring a college football team back to campus and have them play in some sort of mini-biodome situation—in some ways, it might be more a little more practical than trying to do that in professional sports, given that a lot of college football teams already have their own semi-self-enclosed shadow campuses with their own living and training facilities.

There’s also a lot of pressure on athletic departments to consider this, because college football is their major source of revenue. However, I’ve talked to a couple of athletic directors and other administrators, and they’ve all said, ‘hey, if we don’t have students back on campus in the fall, we’re not going to have sports. That just is not going to happen.”

So, based on where we are now, are colleges and universities likely to have their student bodies back on campus this fall?

I've been asked about college football a lot. And I really struggle with that. I agree that it would be weird to have a football team back when the university itself isn't operating. 

I think one of the things that's important to understand is that one of the reasons we had to be so strict and so broad-based with what we are doing as a society is that we had no idea where the virus was—all we knew is that it was transmitting widely, somewhere. And so when you can't target interventions to specifically hard hit areas like an individual city—or even an individual college campus—you have to take these seemingly draconian measures.

Here’s a football metaphor for it. Playing defense 11-on-11 is hard enough when you’re facing a high-powered offense like COVID-19. But the situation we were in was like if the offense had snuck four extra guys on the field, and now your secondary is trying to cover nine receivers. I don't care how good you are—you can't do that! So we had to beg the refs to blow the whistle and stop the game until we can force those four extra guys off the field. And that's the process that we're in now with social distancing and flattening the curve and all of that.

So back to colleges. If you look at the CDC guidance for, say, shutting down schools, whether you should be shutting down K-12 schools depends on the amount of community-based, person-to-person transmission in your area. If we do a really good job of getting the virus contained and continuing to contain it—by which I mean, again, having very, very few new cases emerging among Americans; and being able to test for and identify a large percentage of those cases in near-real time and isolate those people, ideally away from their families so that they don't spread it to them; and then find who they've been in close contact with and warn them and ask them to quarantine as well, to make sure that they're not infected—if we can get to the point where we're doing that, then that allows us to start slowly releasing various restrictions. 

Could that get to the point where you have colleges back in session? I really don't know. But I'm not going to say absolutely not.

It’s all on the continuum. Maybe you can have colleges back in certain areas but not others. How would that work if you're trying to bring back college football, like in the SEC, and you have students allowed back to a half-dozen schools but not the others? I don’t know what you would do with that.

Oh God, I could imagine SEC fans doing crazy things like trying to get a rival school infected and shut down.

That would unfortunately not shock me! [Laughs]

Me neither! [Laughs]

Joking aside, it’s really hard to look into the crystal ball for college sports because it depends on college being in session, and I just don’t think we have a good handle on that.

Everything with this pandemic is going to be so dependent on the situation on the ground, which is just changing every damn day. There is just a lot of unknown. I mean, there’s a school of thought that “this is going to be Armageddon, and that's obvious,” and another school of thought that’s like, “it’s going to be fine and we're going to be back to work in a month, and how can you think otherwise?”

But all of this is dependent on what we do now. We don't need models to know that we're in a very, very dangerous, dangerous situation. And sports is actually a good way to talk about how we control this—if you want sports back, be good now. Listen to your coaches and don’t freelance. We’re all in this together. We have to be a part of a team. And we have to be pulling in the same direction.

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