The nightmare returns.

In Indonesia, gravediggers work until the end of the night, for lack of oxygen and vaccines. In Europe, countries are slamming their doors again, with quarantines and travel bans. In Bangladesh, urban garment workers fleeing an impending closure are almost certainly sowing another wave of coronavirus in their impoverished home villages.

And in countries like South Korea and Israel that appeared to have largely defeated the virus, new groups of diseases have proliferated. Chinese health officials announced Monday that they will build a giant quarantine center with up to 5,000 rooms to accommodate international travelers. Australia has ordered millions of people to stay at home.

A year and a half after starting to travel the world with exponential efficiency, the pandemic is on the rise again in large parts of the world, in large part thanks to new variants, especially the highly contagious Delta variant identified for the first time. in India. From Africa to Asia, countries are suffering record numbers of Covid-19 cases and deaths, even as wealthier countries with high vaccination rates have lowered their guard, dispensing with warrants mask and reveling in a life returning to normal.

Scientists believe the Delta variant may be twice as transmissible as the original coronavirus, and its potential to infect some partially vaccinated people has alarmed public health officials. Unvaccinated populations, whether in India or Indiana, can serve as incubators for new variants that could evolve in surprising and dangerous ways, with Delta giving rise to what Indian researchers are calling Delta Plus. There are also Gamma and Lambda variants.

“We are in a race against the spread of variants of the virus,” said Professor Kim Woo-joo, an infectious disease specialist at Korea University Guro Hospital in Seoul.

Malaysia’s ongoing political debates in the Seychelles – whether to institute lockdowns and mask requirements – are starting to resonate in countries with far more resources, including abundant vaccines. On Monday, health officials in Los Angeles County, where Delta variant infections are on the rise, urged residents, even immune, to wear masks indoors. (However, many scientists say masks are not necessary in areas where the virus is not prevalent.)

But while the new images of Nepal or Kenya of overflowing intensive care units and dying doctors bring terrible memories back to the West, it is not certain that they also give a glimpse of the future.

Most of the existing vaccines appear to be effective against the Delta variant, and early research indicates that those infected are likely to develop mild or asymptomatic cases. But even in the wealthiest countries – with the exception of a handful of countries with small populations – less than half of people are fully immunized. Experts say that with the spread of new variants, significantly higher vaccination rates and continued precautions are needed to bring the pandemic under control.

The smoke rising once again from crematoria in less wealthy countries has highlighted the gulf between the haves and have-nots of the world. Vast inequalities in economic development, health systems and – despite promises from world leaders – access to vaccines made the latest wave much bigger and much more deadly.

“Developed countries have used the available resources because they have the resources and want to protect their people first,” said Dono Widiatmoko, senior lecturer in health and social protection at the University of Derby and member from the Indonesian Public Health Association. . “It’s natural, but if we look at it from a human rights perspective, every life is worth the same.”

And as public health officials keep saying, and the pandemic continues to prove it, as long as a region is affected, no part of the world is immune.

While the Delta variant wreaked havoc in India this spring, when the pandemic killed more than 200,000 people there – an official number that is widely considered too low – and crippled the economy, it also crossed over. national borders, infecting mountaineers on Mount Everest, pro-democracy protesters in Myanmar and travelers at London’s Heathrow Airport. Today, it has been detected in at least 85 countries and is the dominant strain in parts of Europe, Asia and Africa.

The fierce transmissibility of the variant was fully visible in Indonesia, the fourth most populous country in the world.

In May, infections there were at their lowest level since the country was plagued by the pandemic last year. In late June, Indonesia was suffering from a record number of cases as the Delta variant took hold after a dispersed religious holiday by travelers across the archipelago. On Tuesday, the International Federation of the Red Cross and Red Crescent warned the country was “on the brink of disaster.”

Less than 5% of Indonesians have been fully vaccinated and frontline medical workers have been immunized with Sinovac, the Chinese-made vaccine that may be less effective than other inoculations. At least 20 Indonesian doctors who received the two doses of Sinovac have died. But as Western countries rack up what appear to be more potent vaccines, countries like Indonesia and Mongolia have had no choice but to many alternatives made in China.

Hong Kong officials last week suspended passenger flights from Indonesia, and they are doing the same with travel from Britain from July 1.

In May, Portugal attempted to revive its tourism industry by welcoming sun-worshipers from Britain again, despite reports of the Delta variant being spread in that country. Within weeks, the British government had instituted a quarantine for travelers from Portugal, including returning vacationers.

With a sharp increase in cases of Delta variants, Lisbon went into lockdown over the weekend and Germany considered Portugal a “virus variant zone”. Now Portugal has moved away from its tourist welcome and is forcing unvaccinated British travelers to self-quarantine.

Some Portuguese hoteliers are discouraged. Isabel Pereira, owner of a guesthouse, said half of her reservations have been canceled and she understands the concerns of tourists.

“Unfortunately, I can’t even tell them for sure what to expect tomorrow, let alone next week,” she said.

For others, the past repeats itself with turbocharged gear.

In Bangladesh, scientists found that nearly 70% of the coronavirus samples from the capital, Dhaka, taken between May 25 and June 7 were the Delta variant. Coronavirus test positivity rates this week hovered around 25%, compared to 2 percent in the United States.

Bangladesh recorded its highest daily number of cases on Wednesday. The numbers are expected to rise as migrant workers return to their villages ahead of a nationwide lockdown on July 1, potentially exposing these communities to the virus.

The nationwide shutdown means all national public transport networks will be suspended and all stores closed for at least a week. But with Bangladesh’s export-driven economy battered by the pandemic, the government has refrained from idling factories and garment factories.

“These are hard working people,” said Mohammed Nasir, former vice president of the Bangladesh Garment Manufacturers and Exporters Association. “Their immune system is stronger.

If the story of a pandemic sets a precedent, such overcrowded neighborhoods, just like prisons or mass religious gatherings, can turn into petri dishes of infection. However, many garment workers are desperate to keep their jobs, especially with annual bonuses due soon.

Despite promises from various countries and international organizations, vaccine deliveries to Bangladesh have been disappointing. Less than 3 percent of Bangladeshis have been fully immunized.

“We are working to find a balance,” said Mr. Nasir, “between lives and livelihoods. “

Reporting was provided by Muktita Suhartono and Richard C. Paddock in Bangkok, Raphael Minder in Madrid, Amy Chang Chien in Taipei, Taiwan and Yu Young Jin in Seoul.