The International Olympic Committee (IOC) last month announced protocols to prevent the spread of Covid-19 at the upcoming Tokyo Olympic Games. But with the opening ceremony now just over a week away, some infectious disease experts are warning the planned precautions may be insufficient.

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Why the Tokyo 2020 Olympics are happening in 2021

Last year, the IOC and Japan decided to postpone the planned Tokyo 2020 Olympic Games due to the then-emerging Covid-19 pandemic.

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At the time, Japan had 865 active Covid-19 cases. Now, Japan is in a state of emergency, with 70,000 active cases. Even so, the Olympic Games—which will maintain the "Tokyo 2020" branding—are scheduled to kick off on July 23.

To prevent the coronavirus from spreading, spectators have been banned from the events. The IOC is also requiring athletes, trainers, and members of the media to follow extensive requirements for testing and social distancing.

The IOC's protocols: Testing, social distancing, travel restrictions—and more testing

The IOC's protocols include several layers of protections.

First, the IOC is offering vaccinations to all athletes—although athletes are not required to accept them. The committee announced last month that Pfizer and BioNTech would donate doses of their vaccines to support the effort, and the IOC predicts that 85% of athletes will be fully vaccinated before the Games start.

Second, all athletes who are traveling internationally will be tested twice for Covid-19 in the days before they depart for Japan—as well as upon arrival and each day during the Games. Those who test positive will be isolated, and contact tracing will be undertaken.

Third, athletes must wear masks nearly all the time unless eating, drinking, sleeping, training, or competing. They must also remain two meters apart from each other, and hugs and high fives are discouraged.

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Finally, athletes and foreign media will be limited in where they can go outside of official games venues. The IOC has defined a limited list of permitted destinations for athletes, and foreign media will likely be tracked via GPS to ensure they don’t go to non-cleared locations, NPR reports.

Brian McCloskey, chair of an independent expert panel advising the IOC on Covid-19 countermeasures, said, "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."

"[I]ndividual cases are inevitable," he said, but "the goal of the regulations is to prevent transmission chains and clusters from forming."

Why some experts warn the IOC's precautions could be insufficient

But some independent experts worry that the IOC's strategies still leave vulnerabilities that could allow outbreaks to occur.

For instance, while athletes will be tested daily, others associated with the Olympic Games will be tested less frequently, depending on their role. They may also be less likely than athletes to be fully vaccinated.

Annie Sparrow, a professor at Icahn School of Medicine at Mount Sinai, said, "What about the workers, the volunteers, the bus drivers exposed for 14 to 16 hours a day who are going into the village and then going back home to their families?"

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Joseph Fauver, an associate research scientist at Yale School of Public Health, added, "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."

Another concern is ventilation, according to Michael Osterholm, director of the Center for Infectious Disease Research and Policy at University of Minnesota. "The last check-in we had with them, in their Olympic Village apartments, there wasn't the kind of adequate ventilation that would substantially reduce the spread of the virus," he said.

In a recent perspective in the New England Journal of Medicine, Sparrow, Osterholm, and other experts called for the IOC to implement varying levels of coronavirus precautions for different sports. They suggested, for instance, that while outdoor sporting events that naturally space out competitors could be considered "low risk," indoor contact sports could be classified as "high risk" and require greater precautions. So far, however, the IOC has declined to implement such a tiered approach.

A potential 'global superspreading event'

But perhaps the biggest concern for public health experts is that, because the Olympics are an international event, an outbreak that starts in Japan could ultimately spread much more widely.

"It's a perfect opening scene for a thrilling movie where everyone gets sick with [the delta variant] all over the world, and they trace it to the Olympics," Peter Chin-Hong, an expert in infectious diseases at University of California, San Francisco, warned.

He added, “The Olympics are not only just a local potential superspreading event in a poorly vaccinated country but [could perhaps become] a global superspreading event.” (Bender, Scientific American, 7/13; Sparrow, et al., New England Journal of Medicine, 7/1; Reed, Axios, 7/14; Wamsley, NPR, 6/9)