Emily Kwong

Michael Zamora and Ben de la Cruz/NPR / YouTube

Scientists have learned a great deal about how the novel coronavirus spreads.

Just over a century ago, a virulent flu outbreak was wreaking havoc on the world.

We know it now as the 1918 influenza pandemic, and its tremors were felt far and wide. By the end of its spread, tens of millions were dead.

The field of public health has taken a giant leap from the days of 1918, when virology was still in its infancy. Today, information is instantaneous and vaccines are in widespread use.

Virus researchers say there is virtually no chance that the new coronavirus was released as result of a laboratory accident in China or anywhere else.

The assessment, made by more than half-a-dozen scientists familiar with lab accidents and how research on coronaviruses is conducted, casts doubt on recent claims that a mistake may have unleashed the coronavirus on the world.

Copyright 2020 NPR. To see more, visit https://www.npr.org.

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Updated at 4:28 p.m. ET

Three weeks ago, Washington, D.C., resident Rebecca Read Medrano started feeling unwell. She had a dry cough, fatigue, nausea and terrible stomach pains that had her bending over.

There was one more symptom, and it was a bit odd. Medrano had largely lost her sense of taste. "My cousin was cooking, and everything he made tasted weird," she recalls.

Updated at 7:49 p.m. ET

Iran will no longer honor its commitment to limit its enrichment of uranium, stepping away from a key component of the landmark nuclear deal it agreed to with six nations, including the United States, in 2015.

The announcement was reported Sunday in Iranian state media. It marks the latest in the country's retreat from the limitations agreed to in the agreement, known as the JCPOA.

The outbreak of wildfires in Australia has reached a tipping point. Thousands of residents were evacuated this week, as bush fires reached the suburban fringes of Sydney, the skies turning blood-red. Coastline towns in the states of New South Wales and Victoria were consumed by the blaze, leaving thousands homeless. Many are stuck behind fire lines, trapped without power or cell service.