The good medical news caused equities to rally, despite mounting deaths worldwide and abysmal economic figures caused by the COVID-19 crisis.
Data showed the pandemic, which has killed more than 224,000 people, has plunged the United States into its worst economic slump in a decade, and has left Germany expecting its biggest recession since the aftermath of World War II.
But for the first time since the new disease was detected there in mid-February, South Korea reported zero new infections.
The East Asian nation had the world’s second-largest coronavirus outbreak for a period after the virus emerged in China late last year.
But with an aggressive test-and-trace strategy and widespread social distancing, it has managed to bring the spread of the pathogen under control.
“This is the strength of South Korea and its people,” said President Moon Jae-in as he announced the milestone.
Meanwhile in the first proof of successful treatment, a clinical trial of the drug remdesivir showed that patients recovered about 30 percent faster than those on a placebo.
“The data shows that remdesivir has a clear-cut, significant, positive effect in diminishing the time to recovery,” said Anthony Fauci, the top US epidemiologist.
South Korea’s virus death toll is around 250- vastly lower than that of Italy, Britain, Spain and France, which have each recorded more than 24,000 fatalities, and the United States, topping the table with a third of global deaths.
Other parts of the region have seen similar success in their fight against the virus.
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Infections have dwindled in China after it imposed extremely strict lockdown measures on millions of people earlier this year. Its official toll is around 4,600, although doubt has been cast on the figures’ accuracy.
Hong Kong, a city of seven million where there have been just four virus deaths, reported no new cases for the fifth straight day on Thursday.
And New Zealand has declared the battle won against widespread, undetected community transmission.
However the economic costs are beginning to mount, raising fears of an era-defining global crash and increasing pressure worldwide to ease lockdowns despite fears of a second wave of contagion.
The US announced that economic output collapsed 4.8 percent in the first quarter- ending more than a decade of expansion.
On Thursday, France and Spain both said their economies had fared even worse, contracting 5.8 percent and 5.2 percent respectively, while the Eurozone economy as a whole also shrank.
Federal Reserve chairman Jerome Powell warned worse was to come, and economic activity will likely drop “at an unprecedented rate” in the second quarter.
Germany, Europe’s largest economy, has succeeded in holding off the devastating death tolls seen elsewhere, but is still bracing for an overwhelming economic hit.
Germany “will experience the worst recession in the history of the federal republic” founded in 1949, economy minister Peter Altmaier warned, predicting that GDP would shrink by a record 6.3 percent.
The International Labour Organization said half the global workforce- around 1.6 billion people- are in “immediate danger of having their livelihoods destroyed”.
One of the worst-hit sectors is the aviation industry, but an unprecedented drop in demand for fossil fuels means global energy emissions are expected to fall a record eight percent this year, the International Energy Agency said.
Experts have warned that only a vaccine will allow the full removal of restrictions that this year put half of humanity under some form of lockdown.
But there have been encouraging signs in the search for a treatment.
Fauci likened remdesivir to the first retrovirals that worked, albeit with modest success, against HIV in the 1980s.
The drug failed in trials against the Ebola virus, and a smaller study, released last week by the WHO, found limited effects among patients in the central Chinese city of Wuhan, the disease’s original epicentre.
Senior WHO official Michael Ryan declined to weigh in on the latest findings, saying he had not reviewed the complete study.
“We are all hoping- fervently hoping- that one or more of the treatments currently under observation and under trial will result in altering clinical outcomes” and reducing deaths, he said.
While the world keeps looking for signs of progress against the pandemic, research is also revealing frightening new details about COVID-19.
Britain and France have both warned of a possible coronavirus-related syndrome emerging in children- including abdominal pain and inflammation around the heart.
“I am taking this very seriously. We have absolutely no medical explanation at this stage,” French health minister Olivier Veran said.
Experts have also warned of longer-term psychological tolls on both children and adults after weeks or even months in isolation.