China is testing restaurant workers and delivery drivers block by block. South Korea tells people to carry two types of masks for differing risky social situations. Germany requires communities to crack down when the number of infections hits certain thresholds. Britain will target local outbreaks in a strategy that Prime Minister Boris Johnson calls “Whac-A-Mole.”

Around the world, governments that had appeared to tame the coronavirus are adjusting to the reality that the disease is here to stay. But in a shift away from damaging nationwide lockdowns, they are looking for targeted ways to find and stop outbreaks before they become third or fourth waves.

While the details differ, the strategies call for giving governments flexibility to tighten or ease as needed. They require some mix of intensive testing and monitoring, lightning-fast response times by the authorities, tight border management and constant reminders to their citizens of the dangers of frequent human contact.

The strategies often force central governments and local officials to share data and work closely together, overcoming incompatible computer systems, turf battles and other longstanding bureaucratic rivalries. Already, in Britain, some local officials say their efforts are not coordinated enough.

The shifting strategies are an acknowledgment that even the most successful countries cannot declare victory until a vaccine is found. They also show the challenge presented by countries like the United States, Brazil and India, where the authorities never fully contained initial outbreaks and from where the coronavirus will continue to threaten to spread.

“It’s always going to be with us,” said Simon James Thornley, an epidemiologist from the University of Auckland in New Zealand. “I don’t think we can eliminate the virus long term. We are going to need to learn to live with the virus.”

Even in places where the coronavirus appeared to be under control, big outbreaks remain a major risk. In Tokyo, there have been 253 new infections in the past week, 83 from a nightlife district. In Gütersloh in western Germany, more than 1,500 workers from a meat processing plant tested positive, prompting the authorities to shut down two districts. South Korea, another poster child for fast responses, has announced dozens of new infections in recent days.

In Rome, which recently emerged from one of the strictest lockdowns in Europe, 122 people have been linked to a cluster case at a hospital, the San Raffaele Pisana Institute. Several days later, 18 people who lived in a building with shared bathrooms came down with the virus.

“As soon as we lowered our guard,” said Paolo La Pietra, who owns a tobacco shop in the neighborhood, “it hit us back.”

Some countries, like South Korea and Japan, aimed to make their responses nimble.

South Korea calls its strategy “everyday life quarantine.” The country never implemented the strict lockdowns that were seen in other places, and social-distancing measures, while strongly encouraged, remain guidelines. Still, it has set a strict target of a maximum of about 50 new infections a day — a target that it says its public health system, including its testing and tracing capacity, can withstand.

Officials shift the rules as needed. After a second wave of infections broke out in Seoul, city officials made people wear masks in public transportation and closed public facilities for two weeks.

The South Korean government has added new guidelines as it has learned more about outbreaks. It advises companies to have employees sit in a zigzag fashion. Air-conditioners should be turned off every two hours to increase ventilation, it said. It has discouraged singing in markets and other public places.

It has also advised people to carry two types of masks in summer — a surgical mask and a heavy-duty mask, similar to the N95 respirator masks worn by health care workers, to be used in crowded settings.

Japan, which endured only limited lockdowns, also wants to keep its limits light to help restart its economy. It is considering allowing travelers from Australia, New Zealand, Thailand and Vietnam. As an island nation, Japan cannot afford to keep its borders closed any longer, said Shinzo Abe, its prime minister.

Last Friday, Japan launched a contact tracing app that would alert users if they had been in touch with a person who tested positive in the last 14 days. Railway operators have launched an app and websites telling commuters how crowded the trains are at any given time.

Officials are also warning people constantly to change the way they live. Though bars and clubs are reopening, hostesses have been told to refrain from being next to a client when singing karaoke and dancing. Nightclubs must minimize music and crowd volumes to reduce the spread of respiratory droplets. Citizens are advised to continue avoiding the “Three Cs” — closed, crowded and close-contact activities.

“We need to run the economy strongly by controlling the infection risks with less-restrictive measures and take measures which put more emphasis on protecting jobs and life,” said Mr. Abe.

Some countries, like China, are learning to ease back from their more draconian methods. The Chinese government virtually isolated tens of millions of people in the city of Wuhan and surrounding Hubei Province when the outbreak began.

Mindful of the economic damage, Chinese leaders have adopted looser restrictions. In Beijing, officials told residents that they could take off their masks outdoors. Temperature screening in the city became less widespread.

Then, on June 12, Beijing officials announced that 53 people had tested positive for the coronavirus. Instead of locking up the capital city, officials promptly shut down a market and residential communities surrounding it and mobilized close to 100,000 community workers to test roughly 2.3 million residents in about a week.

“A city as big as Beijing can’t be in a state of wartime resistance forever,” said Mao Shoulong, a professor of public policy at Beijing’s Renmin University. “How many more times can we endure this?”

Unlike Wuhan, the effort was targeted. Other Beijing neighborhoods stayed open as usual. The Chinese government tends to favor a mass testing approach focused on specific groups — in addition to the people connected to the market, it said it would also test residents living in high- and medium-risk neighborhoods, restaurant and retail staff, students and teaching staff, and health care workers.

China’s strategy is not to bring infections to zero, said Zhang Wenhong, an adviser to the Shanghai government on the pandemic. Instead, in an interview with China’s Caixin magazine, he described China’s game plan as “getting close to zero cases.”

“Prevention and control with precision, coupled with rapid medical treatment,” Dr. Zhang said. “This strategy will be applicable to China for a long time.”

European governments are also learning to be more flexible following their strong responses, though the process can be slow. In Germany, officials have stipulated that regions or municipalities that register more than 50 new infections per 100,000 people in seven days must quickly respond to quell the outbreak, using tools like school closings, full quarantines and mass testing.

Though many of these efforts are intensely local, they require close coordination with central officials and neighboring jurisdictions. England, for example, is exploring limited, tailor-made shutdowns around clusters of infections, but local officials warn that the system is full of potential holes.

Health officials in England, Wales, Scotland and Northern Ireland are largely responsible for their own strategies. In England, where local officials have complained about a lack of testing data from the central government, employers or building managers have picked up the slack by keeping track of infections and respond to outbreaks. Some, like the headquarters of a major retailer in East Lancashire, have been praised by public health officials for taking quick action.

But controlling the virus would require an understanding of where it is lurking, especially difficult for a disease in which 80 percent of the cases have mild symptoms. Several local public health directors said in interviews that they learned about outbreaks from the news. The level of detail that officials need to decide on localized shutdowns — the postal codes of people testing positive, for example — remains elusive.

“Every pandemic begins as a local outbreak,” said Lincoln Sargeant, the director of public health in North Yorkshire. “It’s granular intelligence that we need in a timely fashion.”

Mr. Johnson, the prime minister, has maintained that local shutdowns are sufficient to control new waves of the virus. In the beginning, the government “had very few instruments at our disposal,” he said on Friday. Now, he said, officials can “identify outbreaks where they happen.”

He has likened the effort to Whac-A-Mole, the decades-old arcade game. Officials can “take the preventive measures necessary on the spot, rather than going back to the national lockdown approach,” he said. “That’s what we hope.”

In Rome, the outbreak at the San Raffaele Pisana Institute tested the ability of the local authorities to find and stop outbreaks.

Local health officials tested patients and staff at the hospital, emptied three wards and sealed off the building. Former patients and their contacts queued in their cars outside drive-in testing stations. Rome’s prosecutors opened an investigation into clusters’ origin.

One of the people who became ill was a pulmonologist, Vittorio Bisogni. He came down with a slight fever after he visited a patient who had been released from the hospital. Dr. Bisogni was diagnosed with the virus on June 9. His patient died a few days later.

“I got angry,” Dr. Bisogni said, “After getting hit so hard, we can’t afford to be so naïve.”

Reporting was contributed by Hisako Ueno in Tokyo, Su-Hyun Lee in Seoul and Christopher F. Schuetze in Berlin. Liu Yi contributed research.