Germany's low fatality rate is because of his country's ability to test early and often. He estimates Germany has been testing around 120,000 people a week for COVID-19 during the monthlong period from late February to now, when it's reached epidemic proportions in the country, the most extensive testing regimen in the world.

In other words, Germany's equivalent to the U.S. Centers for Disease Control and Prevention — the Robert Koch Institute — makes recommendations but does not call the shots on testing for the entire country. Germany's 16 federal states make their own decisions on coronavirus testing because each of them is responsible for their own health care systems.

When Drosten's university medical center developed what became the test recommended by the World Health Organization, they rolled these tests out to their colleagues throughout Germany in January.

"And they of course rolled this out to labs they know in the periphery and to hospital labs in the area where they are situated," Drosten said. "This created a situation where, let's say, by the beginning or middle of February, testing was already in place, broadly."