Coronavirus outbreaks have lucah inenglishsome glaring things in common.

Even though people crowded into Wisconsin bars Wednesday night, there's definitive evidence that big spreading events happen indoors— at restaurants, workplaces, and other gatherings — where there's close contact with others (though the outdoors aren't nearly risk-free). And in the U.S., a nation that's generally seen at least 20,000 new cases each day for well over a month, the risk of infection is still alive and well, even if your local bar or barber is now open for business. Over half of states have stubborn infection numbers that won't decline, or are even rising.

"Anyone who thinks we’re past this peak is not reading the data correctly," said Mark Cameron, an immunologist at Case Western Reserve University who previously helped contain the outbreak of another deadly coronavirus, SARS, in 2003.

"Just because things are opening up doesn't mean the risk has gone away," noted Samantha Penta, an assistant professor of emergency preparedness at the University at Albany who researches health and medical care in crises.

So it's prudent to stay aware of the risk of indoor gatherings at this relatively early stage of the pandemic. It's overwhelming clear the virus can effectively circulate inside where people are talking or socializing, either by respiratory droplets falling on surfaces or traveling short distances in the air, like from talking (larger droplets travel a few feet, smaller particles can travel farther). On the 11th floor of an office building in South Korea, one infected person infected 94 other people. At a choir practice in Washington state, 52 of 61 people got COVID-19. It infected over half of the party-goers out of some 50 people who attended a Connecticut "soirée." An air conditioner helped spread the virus to people at a restaurant in Guangzhou, China.

"We know the virus can spread easily among close contacts," said Cameron.

In new coronavirus research on speech droplets published Wednesday, scientists found "substantial probability that normal speaking causes airborne virus transmission in confined environments."

If the over 84,000 reported COVID-19 deaths in the U.S. (as of May 14) isn't a poignant enough number to demonstrate the graveness of this contagion, consider that the country has "only" lost some 84,000 lost souls because of the hardcore social distancing measures that have been implemented for months. They have helped flatten the rising curve of infections, noted Penta. Most bars and restaurants across the nation have been closed (except for take-out) for around two months. Music festivals have been canceled. The NBA was canceled.

And now, masking has become normal. This will likely help reduce coronavirus transmissions in places where people can't stay at least six feet apart, said Cameron, who encourages wearing masks. Yet, he noted it's still unknown exactly how effective masks are at limiting coronavirus transmissions. If you're infected, cloth masks reduce the number of virus particles that you exhale into the air. But they're not a shield.

Mask-wearing also stops people from directly touching their mouth and nose, experts say, and generally serves to remind folks that we're living amid a pandemic with a novel virus we still don't fully understand.

Gatherings at restaurants, schools, or similar places where people share space and surfaces, then, remain ripe for igniting spread. That's because it's unknown who is and isn't infected in the U.S. There's no regular testing. In total, 10.2 million tests have been reported in the U.S. (as of May 13). That's about three percent of the population tested for an infection (not immunity) at a single point in time. This means we're currently ignorant about who's capable of showing up somewhere and spreading disease.

"We're going to have to watch for new outbreaks, because they will occur," said Cameron, referencing the opening of places like restaurants. "It's really a recipe for inviting a second wave [of coronavirus infections] — not this fall, but right now."

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It's critical, then, to remain vigilant inside higher-risk settings. This could be at a place you must go for a short trip (like a market), but especially for longer, voluntary trips (like airplanes or bars). "This is a virus that we know is very happy to take advantage of people being careless," said Dr. Vince Silenzio, an M.D. and professor at the Rutgers School of Public Health.

Months into this pandemic, the only tools available to avoid infection are the same tried-and-true public health measures: constant hand-washing, masking, and avoiding groups. There are no proven medical treatments for quelling a COVID-19 infection, and the prospect that we're all waiting for — a vaccine — doesn't exist and likely won't be available for at best a year to 18 months.

That's the reality, for perhaps a year or longer. Take it from experts who know pathogens best. "I wash my hands incessantly," said Thomas LaVeist, dean of the School of Public Health and Tropical Medicine at Tulane University.

Though LaVeist noted the evidence shows indoor settings are much more likely to facilitate infection, he recommends being aware of the risk outdoors, too. Many people press the same crosswalk button and open the same doors. "Don’t let your guard down," LaVeist recommended.

Of course, the risk of contracting or spreading disease isn't the same in all places. But in the U.S. overall, cases are "still smoldering" noted Rutgers' Silenzio, as the majority states aren't seeing declining numbers. The virus is still out there, in a big way. "It's not a smart place to be from an epidemiological perspective," Silenzio said.

Spending time indoors with groups of people is particularly problematic with this new coronavirus because it's a devious pathogen: Around one in four infected people don't experience symptoms, meaning they're asymptomatic. It's possible to unwittingly spread this virus.

"People need to think carefully about the risks they expose other people to," said the University at Albany's Penta. "They could be asymptomatic."

And just because a governor or mayor deems it OK to spend time at indoor, public settings at this stage of the pandemic, it certainly doesn't mean anyone should. "If political leaders want to run experiments, that doesn't mean you have to be one of the guinea pigs," said Silenzio.

(Importantly, even if places like restaurants and music venues are too risky to visit indoors right now, there are ways to support businesses and artists until the nation's infection rate is quashed and testing is ramped up.)

We're on the doorstep of summer, but the nation isn't in ideal shape for gatherings. The federal government failed to contain the virus, and it's become pervasive in many regions. The CDC expects tens of thousands of more deaths this summer.

"We have more cases and deaths than every other country," said Tulane's LaVeist. "Think about that."