“During biblical times, Noah was the only one who took the rain serious. Everybody else died. The coronavirus is the rain,” the former “Saturday Night Live” cast member intoned in the late-March clip.

“We’re all in this together. But we’ve got to stay six feet apart,” Rock continued, with a quip about his uncut hair.

The one-minute, 10-second video was Rock’s creation, but it was inspired by an unusual nonpartisan coalition of experts who are repurposing new technologies to keep the most vulnerable populations safe by providing them with clear guidance. They are drawing on behavioral science, social media savvy, lessons from political campaigns and their own connections to persuade influencers such as Rock to spread their messages.

And they are acting against the backdrop of a rising communications crisis in public health – the failure of researchers to adapt to the rapidly changing media landscape combined with the current politicization of science that has sidelined experts, including officials from the Centers for Disease Control and Prevention.

“Public health’s greatest underused tool is educating the public,” said Alfred Sommer, former dean of the Johns Hopkins Bloomberg School of Public Health. “Now, it is playing catch-up during a pandemic and with an administration that uneducates the public and uses social media to mock facts, experts and expertise.”

Public health campaigns have historically relied on broad-based communications – from the televised antismoking advertisements that began in the late 1960s to the contemporary Click It or Ticket seat belt signs on highway billboards. In times of crisis, officials such as the National Institutes of Health’s Anthony Fauci have stood alongside presidents to present a united front.

The National Organizing Coalition On Virus Information Distribution – or NoCovid project – aims instead to meet people where they are, by determining which counties are most vulnerable and then enlisting celebrity messengers who have followers there along with trusted local leaders such as physicians, fire chiefs and fifth-grade teachers to spread the word.

“That’s a lot better than Dr. Fauci telling Johnny to wear a mask,” said James Carville, the Democratic political consultant who with his wife, longtime GOP strategist Mary Matalin, is at the heart of the operation. “People don’t know what the Hopkins Bloomberg school is,” he said. “But they do know their own doctors, teachers and civic leaders.”

The coalition has developed an online “tool kit” for local leaders with links to resources such as best practices, advice on tailoring messaging and how to find influencers to disseminate their messages.

Steve Azar, a music and cultural ambassador in Mississippi, was already working with the state when John Barry, best-selling author of “The Great Influenza” about the 1918 flu outbreak,contacted him.

“It just made sense,” Azar said. “Us entertainer types becoming a voice and vehicle.”

Former pro-football player and philanthropist Herman Moore felt his ability to reach across party lines and age groups would lend nonpartisan weight to his outreach.

“I’m for the people. Period,” he said. “I try and channel as best I can what is given to me as good information for safety of the people.”

Several of the influencers fit a long-standing risk-communication strategy – of personalizing messages, engaging with the audience and encouraging collective action.

Paralympic athlete Blake Leeper, who turned to the courts recently to fight for the right to compete against able-bodied runners in the Tokyo Olympics, said that when the coalition approached him, he felt his message of resilience would resonate “just because of the things I have been through.”

Twelve-year-old singer Angelica Hale described how her struggle with double pneumonia and a kidney transplant almost a decade ago would show young people that they are not bullet proof.

“I lived through it,” said Hale, who is trying to relay the message to her 2.4 million Facebook followers that exposure to the virus might pose a threat to people like her who are immunocompromised.

The NoCovid mission was launched in late March when Carville published an essay in the Chronicle of Philanthropy gently chiding Barry, his friend, for preaching to the choir when he published an op-ed in the New York Times about lessons from the 1918 flu. In the absence of White House leadership, Carville called on foundations to fund a unified patriotic response that would bridge the country’s political and socioeconomic divides – “a Dream Team made up of top leaders from Hollywood, technology, advertising, public relations, polling, and behavioral psychology,” he wrote, that would target “every micro-slice of the population.”

An initial day-long conference call included Carville, Matalin, Barry and Bryan Cunningham, a cybersecurity and privacy lawyer who acts as moderator, and representatives from Ogilvy, the marketing giant, and Palantir, the data-mining firm co-founded by PayPal’s Peter Thiel.

Rock’s apocalyptic message, posted a few days later, has been viewed more than 47,000 times. When the group’s early data suggested Newport News, Va., was in danger from the virus, comic actress Wanda Sykes went online to warn her hometown, “It’s not just New York, New Jersey, no. This bitch has an E-ZPass. The scientists and experts I trust are convinced the next hotspot will be area code 757.”

A videotaped exchange between Louisiana State University football coach Ed Orgeron and the team doctor was picked up by CBS Sports and ESPN and went viral. And in the weeks since its founding, the NoCovid coalition has grown from eight to about 60, including vaccine researchers and online audience experts who spend hours every week on calls, delving into thorny issues such as the threats to civil liberties and privacy posed by contact tracing.

“This isn’t looking to replace anything that public health is doing,” said Julie Schafer, chief technology officer for Flu Lab, a nonprofit dedicated to vanquishing influenza. Schafer began working on the need for coordination among all levels of government in pandemic preparedness 15 years ago. She described the pooling of such disparate skills as unlike any she had experienced in her career, which included supporting the federal vaccine and antiviral drug response during the H1N1 outbreak in 2009.

The need for localized messaging has become even clearer, she and other coalition members say, as states relax restrictions, often resulting in different regulations – as well as conflicting social and political pressures – on opposite sides of a county or state border. Add to that an administration often at odds with public health officials from Fauci on down.

Those competing forces fly in the face of what experts on public health messaging say is the key to success – to sustain advice and back it, when possible, with policy even when it is controversial and pits the needs of the community against personal behaviors such as the right to smoke in public buildings or not to wear a seat belt.

“If covid messages are not sustained, people will revert to old behaviors,” said Barbara Loken, an expert in brand management, health promotion and consumer psychology at the University of Minnesota who co-authored a 2010 paper in the Lancet medical journal on the use of mass media to change health behaviors.

The changes asked of people have to feel doable, particularly when risks and resources vary across geographic areas, said Renata Schiavo, a health communication expert at Columbia University’s Mailman School of Public Health: There’s little point in pushing a handwashing campaign in areas that lack hand-washing facilities.

“Communities are more willing to implement behavior when they feel it is feasible and the barriers to that behavior have been removed,” Schiavo said.

But many scholars agree that public health officials have been slow to recognize the rapid shifts to hyperlocal messaging and to platforms that attract younger generations.

“A leading example of what we don’t know how to do yet relates to covid-19,” said Jay Winsten, director of the Frank Stanton Center for Health Communication at the Harvard School of Public Health. Winsten popularized the designated driver concept through TV sitcoms such as “Cheers,” and has been working on a distracted driving campaign. “There isn’t a lot of smart thinking yet in terms of design of messaging so that it reflects where young people are coming from and whether or not there are alternative messaging concepts that might resonate in a stronger way,” he said.

Winsten suspended a course he used to teach on communication skills at Harvard because the cases were derived from the pre-social media world.

“No one has really fixed the model of health communications for the 21st century,” he said.

And while many health communications experts recognize they were lagging behind, none say they were ready for the current politicization of science – and for President Trump’s relentless questioning of scientific data.

“He repeatedly parades forth public health experts only to ignore and then belittle their advice to the public,” said Sommer, the former Johns Hopkins dean, using Trump not wearing a mask as an example.

At the same time, the CDC has lost its voice of authority.

“What they were really good at was foreshadowing: Here’s what we know; here’s what we don’t; and here’s what we are doing,” said coalition member Bruce Gellin, president of Global Immunization at the Sabin Vaccine Institute, who used to work at the CDC. “That’s what we don’t get from anybody now.”

As the states relax their regulations, complicating the simple stay-at-home message, the coalition is awaiting data on the effects of reopening strategies to inform new messaging, as well as examining ways to measure its impact by tracking comments and retweets with the #nocovid hashtag.

“Until there is some sort of post-mortem, you won’t know if you were really effective or contributing materials out of good will,” said Chris Graves, a coalition member and expert on behavior change at Ogilvy.

In the face of a deadly pandemic, he added, “We are prepared to do that.”