Terrifying though the coronavirus may be, it can be turned back. China, South Korea, Singapore and Taiwan have demonstrated that, with furious efforts, the contagion can be brought to heel.

Whether they can keep it suppressed remains to be seen. But for the United States to repeat their successes will take extraordinary levels of coordination and money from the country’s leaders, and extraordinary levels of trust and cooperation from citizens.

There is a chance to stop the coronavirus. This contagion has a weakness.

Although there are incidents of rampant spread, as happened on the cruise ship Diamond Princess, the coronavirus more often infects clusters of family members, friends and work colleagues, said Dr. David L. Heymann, who chairs an expert panel advising the World Health Organization on emergencies.

No one is certain why the virus travels in this way, but experts see an opening nonetheless. “You can contain clusters,” Heymann said. “You need to identify and stop discrete outbreaks, and then do rigorous contact tracing.”

In interviews with a dozen of the world’s leading experts on fighting epidemics, there was wide agreement on the steps that must be taken immediately. Those experts included international public health officials; scientists and epidemiologists; and former health officials in both Republican and Democratic administrations.

Americans must be persuaded to stay home, they said, and a system put in place to isolate the infected and care for them outside the home. Travel restrictions should be extended, they said; productions of masks and ventilators must be accelerated, and testing problems must be resolved.

“The American way is to look for better outcomes through a voluntary system,” said Dr. Luciana Borio, who was director of medical and biodefense preparedness for the National Security Council before her unit was disbanded in 2018. “I think you can appeal to people to do the right thing.”

What follows are the recommendations offered by the experts interviewed by The New York Times.

Scientists must be heard

The White House holds frequent media briefings to describe the administration’s progress against the pandemic, often led by President Donald Trump or Vice President Mike Pence, flanked by a rotating cast of officials.

Many experts declined to speak on the record for fear of offending the president. But they were united in the opinion that politicians must step aside and let scientists both lead the effort to contain the virus and explain to Americans what must be done.

Above all, the experts said, briefings should focus on saving lives and making sure that average wage earners survive the coming hard times — not on the stock market, the tourism industry or the president’s health. There is no time left to point fingers and assign blame.

“At this point in the emergency, there’s little merit in spending time on what we should have done or who’s at fault,” said Adm. Tim Ziemer, who led the pandemic response unit on the National Security Council before its disbanding. “We need to focus on the enemy, and that’s the virus.”

Stop transmission between cities

The next priority, experts said, is extreme social distancing. If it were possible to wave a magic wand and make all Americans freeze in place for 14 days while sitting 6 feet apart, epidemiologists say, the whole epidemic would sputter to a halt.

Obviously, there is no magic wand. But the goal of lockdowns and social distancing is to approximate such a total freeze. To attempt that, experts said, travel and human interaction must be reduced to a minimum.

Stop transmission within cities

Within cities, there are dangerous hot spots: One restaurant, one gym, one hospital, even one taxi may be more contaminated than many identical others nearby because someone had a coughing fit inside.

Each day’s delay in stopping human contact, experts said, creates more hot spots, none of which can be identified until about a week later, when the people infected there start falling ill.

To stop the explosion, municipal activity must be curtailed. Still, some Americans must stay on the job: doctors, nurses, ambulance drivers; police officers and firefighters; the technicians who maintain the electrical grid and gas and phone lines. The delivery of food and medicine must continue.

But the weaker the freeze, the more people die in overburdened hospitals — and the longer it ultimately takes for the economy to restart.

Fix the testing mess

Testing must be done in a coordinated and safe way, experts said. The seriously ill must go first, and the testers must be protected.

In the United States, people seeking tests are calling their doctors, who may not have them, or sometimes waiting in traffic jams leading to store parking lots. On Friday, New York City limited testing only to those patients requiring hospitalization, saying the system was being overwhelmed.

Isolate the infected

As soon as possible, experts said, the United States must develop an alternative to the practice of isolating infected people at home, as it endangers families. In China, 75% to 80% of all transmission occurred in family clusters.

Instead of a policy that advises the infected to remain at home, as the Centers for Disease Control and Prevention now does, experts said cities should establish facilities where the mildly and moderately ill can recuperate.

Wuhan created many such centers, called “temporary hospitals,” each a cross between a dormitory and a first-aid clinic. They had cots and oxygen tanks, but not the advanced machines used in intensive care units.

U.S. cities now have many spaces that could serve as isolation wards. Already New York is considering turning the Jacob K. Javits Convention Center into a temporary hospital.

Find the fevers

Because China, Taiwan and Vietnam were hit by SARS in 2003, and South Korea has grappled with MERS, fever checks during disease outbreaks became routine.

In most cities in affected Asian countries, it is commonplace before entering any bus, train or subway station, office building, theater or even a restaurant to get a temperature check. Washing your hands in chlorinated water is often also required.

Trace the contacts

Finding and testing all the contacts of every positive case is essential, experts said. At the peak of its epidemic, Wuhan had 18,000 people tracking down individuals who had come in contact with the infected.

At the moment, the health departments of some American counties lack the manpower to trace even syphilis or tuberculosis, let alone scores of casual contacts of someone infected with the coronavirus.

Borio suggested that young Americans could use their social networks to “do their own contact tracing.”

Make masks ubiquitous

There is very little data showing that flat surgical masks protect healthy individuals from disease. Nonetheless, Asian countries generally make it mandatory that people wear them. The Asian approach is less about data than it is about crowd psychology, experts explained.

All experts agree that the sick must wear masks to keep in their coughs. But if a mask indicates that the wearer is sick, many people will be reluctant to wear one. If everyone is required to wear masks, the sick automatically have one on and there is no stigma attached.

Also, experts emphasized, Americans should be taught to take seriously admonitions to stop shaking hands and hugging. The “WHO elbow bump” may look funny, but it’s a legitimate technique for preventing infection.

Preserve vital services

Federal intervention is necessary for some vital aspects of life during a pandemic. Only the federal government can enforce interstate commerce laws to ensure that food, water, electricity, gas, phone lines and other basic needs keep flowing.

Trump has said he could compel companies to prioritize making ventilators, masks and other needed goods; some have volunteered. He also has the military; the Navy is committing two hospital ships to the fight. And Trump can call up the National Guard.

High-level decisions like these must be made quickly, experts said.

“Many Western political leaders are behaving as though they are on a tightrope,” said Dr. David Nabarro, a WHO special envoy on COVID-19. “But there is no choice. We must do all in our power to fight this.”

Produce ventilators and oxygen

The roughly 175,000 ventilators in all U.S. hospitals and the national stockpile are expected to be far fewer than are needed to handle a surge of patients.

The manufacturers, including a dozen in the United States, say there is no easy way to ramp up production quickly. But it is possible other manufacturers, including aerospace and automobile companies, could be enlisted to do so.

Providers, meanwhile, are scrambling for alternatives. Canadian nurses are disseminating a 2006 paper describing how one ventilator can be modified to treat four patients simultaneously.

The United States must also work to increase its supply of piped and tanked oxygen, Aylward said.

Retrofit hospitals

Hospitals in the United States have taken some measures to handle surges of patients, such as stopping elective surgery and setting up isolation rooms.

The national stockpile does contain some prepackaged military field hospitals, but they are not expected to be nearly enough for a big surge.

In Wuhan, the Chinese government famously built two new hospitals in two weeks. All other hospitals were divided: 48 were designated to handle 10,000 serious or critical coronavirus patients, while others were restricted to handling emergencies like heart attacks and births.

Decide when to close schools

As of Saturday, schools in 45 states were closed entirely, but that is a decision that divided experts.

“Closing all schools may not make sense unless there is documented widespread community transmission, which we’re not seeing in most of the country,” said Dr. Thomas R. Frieden, a former CDC director under President Barack Obama.

It is unclear how much children spread coronavirus. They very seldom get sick enough to be hospitalized. Current testing cannot tell whether most do not even become infected.

But closing whole school districts can seriously disrupt a city’s ability to fight an outbreak. With their children stuck at home, medical workers cannot come to work.

Recruit volunteers

China’s effort succeeded, experts said, in part because of hundreds of thousands of volunteers. The government declared a “people’s war” and rolled out a “Fight On, Wuhan! Fight On, China!” campaign.

Many people idled by the lockdowns stepped up to act as fever checkers, contact tracers, hospital construction workers, food deliverers, even babysitters for the children of first responders. With training, volunteers were able to do some ground-level but crucial medical tasks.

Americans often step forward to help neighbors affected by hurricanes and floods; many will no doubt do so in this outbreak.

“This truly is an ‘all hands on deck’ situation,” Ziemer said.

Prioritize the treatments

Clinicians in China, Italy and France have thrown virtually everything they had in hospital pharmacies into the fight, and at least two possibilities have emerged that might save patients: the anti-malaria drugs chloroquine and hydroxychloroquine, and the antiviral remdesivir, which has no licensed use.

There is no proof yet that any of these are effective against the virus. Italy and France have trials underway, and hospitals in New York are writing trial protocols now.

Find a vaccine

The ultimate hope is to have a vaccine that will protect everyone, and many companies and governments have already rushed the design of candidate vaccines.

The process will take at least a year, even if nothing goes wrong. The roadblock, vaccine experts explained, is not bureaucratic. It is that the human immune system takes weeks to produce antibodies, and some dangerous side effects can take weeks to appear.

After extensive animal testing, vaccines are normally given to about 50 healthy human volunteers to see if they cause any unexpected side effects and to measure what dose produces enough antibodies to be considered protective.

If that goes well, the trial enrolls hundreds or thousands of volunteers in an area where the virus is circulating. Half get the vaccine, the rest do not — and the investigators wait. If the vaccinated half do not get the disease, the green light for production is finally given.

© 2020 The New York Times Company