By Maddie Bender

When officials postponed the Summer Olympic Games in Tokyo until 2021 last year, the announcement came amid similar decisions from professional sports leagues and regional and national stay-at-home orders. At the time, International Olympic Committee (IOC) organizers hoped that the extra year would buy the world time to get a handle on SARS-CoV-2, the novel coronavirus that causes COVID-19, which had then recently been characterized as a pandemic by the World Health Organization.

The Olympic Games are set to go on later this month, with mitigation efforts such as physical barriers, social-distancing guidelines and viral testing in place to prevent cases from becoming clusters of infection. But as vaccination remains unevenly distributed worldwide—only about 17 percent of Japan’s population is fully vaccinated—and the more transmissible Delta variant spreads, experts warn that those measures may not be enough. Already, several athletes have tested positive for COVID-19 after arriving in Japan, raising concerns of a possible outbreak.

“It’s a perfect opening scene for a thrilling movie where everyone gets sick with Delta all over the world, and they trace it to the Olympics,” says Peter Chin-Hong, an infectious disease specialist at the University of California, San Francisco. “The Olympics are not only just a local potential superspreading event in a poorly vaccinated country but [could perhaps become] a global superspreading event.”

Brian McCloskey, chair of an independent expert panel advising the IOC on COVID-19 countermeasures, says that while individual cases are inevitable, the goal of the regulations is to prevent transmission chains and clusters from forming. But experts interviewed point to risks for viral transmission tied to individual sports and arenas, life in the Olympic Village and seeded infections from the broader community. Altogether, they indicate that without stricter mitigation measures than the ones introduced by the IOC, clusters of infection are likely to propagate.

Sport-Specific Guidance

As it stands, all Olympic athletes must abide by the same guidelines laid out in the official playbook for the games. If flying internationally this month, they must be tested twice in the 96 hours before their flight with an approved polymerase chain reaction (PCR) or antigen test. (Those flying earlier than July 1 were only required to take one test within 72 hours of their departure.) Upon arrival, they will be given a rapid saliva-based antigen test that is processed as they go through immigration and claim their baggage. A positive or inconclusive result will need to be confirmed with a PCR test at the Olympic Village. If athletes test negative, they will be allowed to continue to their accommodations. Daily, they are required to complete a health check using an app and to give saliva samples for an antigen test, followed by a PCR test on the same sample if results are unclear or positive.

When it comes to transmitting a respiratory virus that spreads through fluids, droplets and aerosols, not every sport is created equal. Michael Osterholm, director of the Center for Infectious Disease Research and Policy at the University of Minnesota, co-authored a perspective, first published online in May, that called for a tiered risk-management approach. He and his co-authors wrote that the IOC should have designated different sports as having high, moderate or low COVID transmission risk.

According to the paper’s authors, outdoor events that naturally space out competitors—such as sailing, archery and equestrian competitions—can be considered low risk. Moderate risk events include those that are held outdoors but in which close contact is unavoidable, including rugby, field hockey and soccer. Indoor sporting events that involve close contact, such as boxing and wrestling, are high risk. As a rule of thumb, any indoor sports event is riskier than one held outdoors.

Annie Sparrow, an assistant professor of population health science and policy at the Icahn School of Medicine at Mount Sinai and a co-author of the perspective, says there are sports that fall into gray areas, too: swimming, for example, could be considered low risk for individual events but moderate risk for relays. Water polo, which requires close contact, would be a high-risk sport. These risk assessments could have informed changes in the way certain competitions will be held. For instance, the transmission risks of aquatic events would be lower if they were planned to take place in outdoor pools, Sparrow says.

Simply making these designations is not enough, however, Osterholm says. Organizers should have required more precautions for athletes competing in riskier events. These might include more accurate testing using only PCR assays rather than antigen-based ones or greater restrictions on socializing with anyone other than teammates and coaches. Olympic organizers recently barred spectators from most events after Japan declared another state of emergency in Tokyo over a spike in new COVID cases and fears about the Delta variant.

In the absence of these measures, a one-size-fits-all policy is worrisome, says Joseph Fauver, an associate research scientist at the Yale School of Public Health, who worked on testing strategies for the National Basketball Association (NBA) and National Football League (NFL). “The risk of transmission brought on by team sports that practice together is inherently different from something like doing archery outside,” he says.

McCloskey says the policies were designed not to rely on players’ vaccination status, which varies by country because of access and wealth disparities. He adds that organizers do plan to allow for a sliding scale when it comes to isolation and quarantine. Some athletes who test positive or are identified as a close contact of a case may undergo an “adaptive quarantine” in which they isolate themselves from teammates and staff but are still permitted to train, he says, depending on the nature of the test result and contact.

With regard to whether some high-risk, indoor contact sports events might be canceled, IOC adviser McCloskey says the evidence of transmission events from professional contact sports leagues is weak. “The reality is there’s not a lot of evidence from around the world that COVID has been spread on the field of play in competitions,” he says.

Osterholm strongly disagrees. In Minnesota, for example, a 2021 peak in case numbers in April was partially fueled by high school and grade school sporting events. Another recent case report identified a gymnastics facility in Oklahoma as the root of an outbreak fueled by the Delta variant. Declaring that sports present a low risk of transmission also ignores the risks outside of the competitions themselves, Osterholm says. “What's been missing is an understanding that the Olympics are much more than just an athletic event,” he says.

In response, McCloskey says that the evidence cited only shows an association between sports activity and transmission and not proof that transmission occurred during play. He adds that the guidebook has been designed “to consider the risk holistically across all the activities the participants engage in, both on and off the field of play.”

Risks Outside Of Competition

The official Olympic guidebook contains recommendations for social interactions in the Olympic and Paralympic villages and measures in place to impede viral transmission. These include requirements that players and staff wear a mask unless they are sleeping, eating, drinking, training or competing; that both avoid physical contact, such as handshakes and hugs; and that athletes only go to locations listed in a preapproved “Activity Plan.”

According to experts, some of these measures are more effective than others. Interventions such as reducing tables’ capacity from six people to four in dining areas and placing splash guards and plexiglass barriers around the Olympic and Paralympic villages are “retro,” Chin-Hong says. “It’s like we went back in a time machine” to before it was known that the virus spreads through aerosol transmission, he says.

Osterholm likens aerosol transmission to smelling cigarette smoke: If someone is smoking in an enclosed room, others will be able to smell the smoke even if they are behind plexiglass barriers or if the smoker has already left the room. The IOC has not adequately addressed aerosol transmission in its plans for ventilation, he says—recommendations to open windows will likely not be heeded during Japan’s hot summers. Additionally, IOC guidelines recommend wearing “non-fabric masks where possible” instead of requiring N95 respirators, which are much better at protecting people from aerosols than other kinds of masks. All attendees are allowed to remove their mask when speaking to Paralympians or others who rely on lipreading—with the suggestion that they stay two meters from the athletes.

According to predictions from the IOC, more than 85 percent of athletes and officials in the Olympic and Paralympic villages—and more than 70 percent of media staff in attendance—will be fully vaccinated. These percentages, however, do not extend to support staff, including groundskeepers, food preparation workers or cleaners.

Unlike the NBA when it restarted its 2019–2020 season last year, the Olympics have not been placed in a so-called bubble, Fauver says. “It's crucial that support staff are just as involved as the athletes in testing routinely, in abiding by distancing and masking—because these folks are just as likely to get infected as anyone else is,” he says.

The NBA and NFL also performed real-time genomic sequencing, Sparrow says: public health experts were able to trace the spread of the virus from person to person and to pinpoint specific high-risk interactions and environments. But the IOC opted not to include this technique in its testing program.

The IOC maintains that the mitigation measures in the official guidebook will be enough. “At the moment, we believe the measures that we have in place are sufficient to help us reduce the risk, irrespective of the emergence of the new variants,” McCloskey says.

When cases inevitably occur, though, the spread will affect populations from undervaccinated countries disproportionately. Chin-Hong says this unequal spread is ironic, considering the backdrop of the Olympic Games. “When you think about the Olympics, it’s supposed to be a level ground—you can come from any country and then rise to the top,” he says. “In the face of a pandemic, it actually makes a bigger statement about the ‘haves’ and the ‘have-nots.’”