On the first Sunday in February, as the San Francisco 49ers were in the middle of blowing a lead in the Super Bowl, a small group of doctors in the Bay Area was too busy to care about a football game. They were dealing with the region’s first cases of coronavirus.

They had no time to waste as they raced to bring the University of California San Francisco’s Covid-19 command center into operation. They worked overnight and had it running by the next morning—when two patients confirmed with the virus were transferred to UCSF’s hospital.

There could have been hundreds of thousands of fans on the streets of San Francisco at a Super Bowl parade a few days later.

Some experts who have studied the Bay Area’s containment of the virus have reached a surprising conclusion about these simultaneous events of Super Bowl Sunday: San Francisco likely won when the 49ers lost.

The Kansas City Chiefs’ comeback wasn’t just exhilarating. It also might have been the best thing that could’ve happened to 49ers fans.


“It may go down in the annals as being a brutal sports loss,” said Dr. Bob Wachter, the chair of UCSF’s department of medicine, “but one that may have saved lives.”

The 49ers had a 10-point lead with seven minutes left in the fourth quarter until quarterback Patrick Mahomes rallied the Chiefs back to an epic win—which means they were seven minutes from a parade in a city where a parade could have been devastating.

Public health experts point to mass gatherings as places where highly contagious viruses spread easily, and championship parades are particularly vulnerable to infectious diseases. They bring together hundreds of thousands—and potentially millions—of screaming, hugging and beer-sharing fans on crowded streets in major cities. They’re ideal breeding grounds for respiratory illnesses. And the timing of this Super Bowl parade could’ve made it a super-spreading event.

“It is certainly hard to imagine a more high-risk situation,” said Dr. Niraj Sehgal, who leads UCSF’s Covid-19 command center.

San Francisco has been widely praised for its response to the virus. Photo: Eric Risberg/Associated Press

There were only a handful of known U.S. patients with the virus on Super Bowl Sunday, but Santa Clara County reported its second case that morning, and neighboring San Benito County later that day confirmed person-to-person transmission of the virus between a man who’d recently traveled to Wuhan, China and his wife.


Dr. Sehgal was already so busy that afternoon that he missed the first half of the Super Bowl. He sneaked away to catch some of the second half with his daughter at a friend’s house, but he was too busy texting to follow the game and watch Mahomes crush the hopes of his colleagues. Dr. Sehgal and his team had been planning to set up their command center on Feb. 3 as a proactive measure, but they would learn late on the night of Feb. 2 that even their precautionary measures were too late: They were receiving their first patients on Monday morning. They had to spend all night getting ready.

It didn’t dawn on him until much later how much that football game he ignored on television might have directly affected his job.

On Dec. 1, 2019, a patient in Wuhan, China, started showing symptoms of what doctors determined was a new coronavirus. Since then, the virus has spread across the world. Here’s how the virus grew to a global pandemic. Photo: Alberto Pizzoli/AFP

San Francisco has been widely praised for its response to the virus. One of the first places in the country to identify local spread of the virus is also one of the places that has contained it best. Experts have attributed this success to early interventions, careful planning and decisive action.

But they also say the Bay Area benefited from events beyond the local government’s control—including the outcome of a football game thousands of miles away.


“Some of it was lucky breaks,” said Dr. Wachter, “and this may be one of the lucky breaks that spared us from a much worse fate.”

It’s impossible to know precisely how many people would have packed the streets to fete quarterback Jimmy Garoppolo, coach Kyle Shanahan and the rest of the 49ers. But it’s possible to offer a rough estimate: a lot of people. When the Golden State Warriors won their three recent championships, the parades in Oakland attracted reported crowds of between 500,000 to 1.5 million fans. “If one person had it and spread it to a number of people at the parade, that could’ve had an impact on the epidemic trajectory,” said Carl Bergstrom, a University of Washington biology professor.

A large crowd gathers to watch the Golden State Warriors victory parade and rally on June 15, 2017, in downtown Oakland, Calif. Photo: Getty Images/Getty Images

It might have even been the modern equivalent of another disastrous parade more than a century earlier.

The city of Philadelphia’s parade to stoke wartime morale on Sept. 28, 1918, is still remembered as one of the most regrettable events in American history. What the 200,000 people who rejoiced didn’t realize was that a deadly strain of influenza was silently incubating. The city’s public health director would acknowledge that Philadelphia was in the middle of an epidemic two days later.


The city was so devastated by the Spanish flu pandemic—and this one unfortunate parade—that its name alone now serves as a powerful warning: don’t be Philadelphia. San Francisco could have unwittingly become Philadelphia.

“It would not have taken much spread in early February for the thing to have gotten way out of hand,” Dr. Wachter said. “That would’ve been enough to light the fire.”

There was another, unluckier city that hosted a raucous party a few weeks later with hundreds of thousands of revelers—including some who were almost certainly infected already. John M. Barry, the author of books about football and flu, happens to live in that city.

“A Super Bowl victory parade may have done what Mardi Gras seems to have done in New Orleans,” Barry said.

But the Chiefs winning the Super Bowl turned out to be a public health savior. Kansas City happened to be one of the last NFL cities to report its first case of the virus, and the hundreds of thousands of long-suffering fans who celebrated on Feb. 5 were about six weeks behind San Francisco. Not until March 18 did Kansas City report its first case. Bay Area residents had been ordered to shelter-in-place by then.

Only recently have Bay Area physicians considered what might have happened if the 49ers had won the Super Bowl. And one doctor reached a conclusion that would’ve been seen as blasphemy in San Francisco when the world was a different place two months ago.

“It made us all feel a bit better about the 49ers’ loss,” Dr. Wachter said.

Write to Andrew Beaton at andrew.beaton@wsj.com and Ben Cohen at ben.cohen@wsj.com