There’s groaning about this quote online today but those of us who’ve been following coronavirus news closely surely must see it as a fait accompli by now.

Under what conceivable circumstances would it be safe and responsible to attend a concert or a major sports event before a vaccine for COVID-19 has been administered to enough people to provide herd immunity?

This is life now. If the Super Bowl is played next year at all, even in front of empty stands, it’ll be a minor miracle.

Emanuel: Yes, restarting the economy has to be done in stages, and it does have to start with more physical distancing at a work site that allows people who are at lower risk to come back. Certain kinds of construction, or manufacturing or offices, in which you can maintain six-foot distances are more reasonable to start sooner. Larger gatherings — conferences, concerts, sporting events — when people say they’re going to reschedule this conference or graduation event for October 2020, I have no idea how they think that’s a plausible possibility. I think those things will be the last to return. Realistically we’re talking fall 2021 at the earliest.

Restaurants where you can space tables out, maybe sooner. In Hong Kong, Singapore and other places, we’re seeing resurgences when they open up and allow more activity. It’s going to be this roller coaster, up and down.

Note well: “At the earliest.” If the vaccine arrives in fall of next year, which is in line with the timeframe of 12 to 18 months, it’ll be months after that before enough of us have gotten the shot to render crowds completely safe again.

If you missed this post a few weeks ago, read it now for a lesson on what a mass gathering can do to seed an apocalyptic local outbreak. Northern Italy still hasn’t recovered from a single soccer match played in Milan on February 19. Coincidentally, there’s another story on the wires today about how devastating a large sports-related gathering could have been if fate hadn’t intervened to cancel it. That would be the San Francisco 49ers’ Super Bowl victory parade, which would have taken place in mid-February — at a moment when virus was starting to circulate in SF — if the Niners had held on to beat the Chiefs. Because they didn’t, the city was spared and now stands as one of America’s major success stories in containing its outbreak.

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…

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.

San Francisco’s mayor, London Breed, has been praised for locking down before most other major American cities did. Containment in the Bay Area is a key reason why California’s epidemic remains so shockingly small. But mid-February was still early in America’s experience with COVID-19 and Breed would have been under immense pressure not to cancel a once-in-a-lifetime party for the Super Bowl champs. The city might have been brought to its knees if the parade had been held.

That same logic will prevent large crowds for the next 18 months. No one wants to risk seeding a new local catastrophe for something as enjoyable but ultimately frivolous as sports or concerts when the country will be stuck struggling to limit new infections every day for the sake of keeping people at work. Even if sports were allowed to let spectators in, odds are that they’d never draw enough to make it worthwhile financially. “I don’t think the marginal customer for a stadium or a concert or a cruise ship is coming back soon,” said Scott Gottlieb to Vox. “I think people are going to be more circumspect about travel, particularly international travel. Businesses are going to be more circumspect about bringing together large groups of people.” There’s not enough hydroxychloroquine in America to get pro sports attendance back to what it was before 2022.

Frankly, I continue not to see how sports will be played even without fans there. There’s too much contact between players in football, basketball, and hockey to avert infection, and once one player is infected, the entire league would screech to a halt as teams were forced to quarantine. Baseball is the one possible exception because contact is minimal, but read this smart SI piece about just how insane the logistical challenge would be for any sport to try to quarantine the entire league so that games could be played safely every day. Not just the players and coaches but all kinds of support staff, from security to transportation to caterers and so on, would need to be locked down together for months. No one could go in or out of the bubble without having to stay off the field in isolation for at least 14 days. If so much as one player got infected due to some lapse, the whole league would shut down for weeks. Imagine how much money might be potentially wasted trying to pull that off only to have it collapse halfway through the season because some idiot snuck out overnight and contracted the bug.

Nothing’s going to make it safe to congregate absent a magic bullet of some kind. A professor at Oxford claimed a few days ago that they’re very confident in their vaccine and might have it ready in six months, but it’s not clear from the story what “ready” means. Ready for human trials? Ready for manufacture? Ready to be administered to the public? I haven’t read anything anywhere that suggests the vaccine timeline is less than a year realistically. The most promising pharmaceutical news lately is the idea that vaccines developed for other diseases might provide partial protection against COVID-19, most notably the BCG vaccine developed years ago for tuberculosis. Researchers have noticed that children vaccinated with BCG seem to be less susceptible to certain other diseases as well, including some respiratory viruses. Some researchers have noticed that developing countries where children get BCG have had noticeably lower fatality rates from COVID-19 so far. There’s a trial going on right now in Boston to see if BCG can lower the severity of coronavirus infections.

Other researchers believe that the data is being misinterpreted, though, and that the spread is lower in countries where BCG vaccinations are common because the disease hasn’t really “arrived” there yet. Even if the vaccine partially works against the virus, it’d have to work surprisingly well to make local authorities comfortable with holding nonessential mass gatherings again. What sort of transmission and fatality rates would be “acceptable” for a city to greenlight a Taylor Swift concert? How many people would need to have gotten the BCG vaccine to make it kinda sorta safe for them to show up?