Despite the precautions in place for the roughly 25,000 fans who attended Super Bowl LV in Tampa, Florida on Sunday, some experts are concerned that the game could be a coronavirus superspreader event.

"On paper it looks reassuring," Dr. Peter Chin-Hong, an infectious disease specialist at the University of California, San Francisco, told Insider. "But the reality is sobering."

Coaches, players, and staff of the Kansas City Chiefs and Tampa Bay Buccaneers had been tested daily throughout the season and recently as much as twice daily, ESPN reported. The 25,000 fans were spread out among Raymond James Stadium's more than 75,000 seats, with 30,000 cardboard cutouts of people used to fill in the empty space.

But while these measures are good, Chin-Hong says there's still a significant cause for concern.

Of those in attendance, 7,500 were fully vaccinated healthcare workers. However, others at the game were not required to be vaccinated or tested in advance, which Chin-Hong said includes more than half of all attendees.

He also said even though the Tampa stadium is open-air, the nature of the event makes it especially risky.

"Any time you have 25,000 potentially inebriated people together shouting, yelping and screaming in one place in the middle of a pandemic, you are bound to have transmission," he said, adding that alcohol increases the likelihood of people not following safety protocols.

Chin-Hong said shouting and yelling helps the droplets that cause COVID-19 to travel much farther than six-foot distancing guidelines. The length of the game, which lasted nearly four hours, also means the virus was more likely to spread, since longer exposure time increases the likelihood of infection from virus-laden aerosols.

The Super Bowl, which was won by the Tampa Bay Buccaneers, also took place in Florida, a state that is still battling its latest coronavirus surge. While its daily case count is dropping, Sunday was the 40th day in a row that the daily COVID-19 death count was in triple digits, The Miami-Herald reported.

Chin-Hong said that emerging coronavirus variants in Florida are another concern, noting recent data from the Centers for Disease Control and Prevention that showed the state has reported more cases of the UK variant than anywhere else in the country.

"The variants circulating are at best more transmissible – at worst, will cause more severe disease and make our vaccines not work as well," he said.

Whether or not coronavirus transmission occurred at the Super Bowl is not a question, Chin-Hong said. "The question is how much."

"And that is just the game – not the parties in Tampa's open bars and in people's private homes."

Photos and videos shared on social media during and after the game confirmed those concerns, with large groups of people gathering without masks.

This article was originally published by Business Insider.