CDC scientists began working sixteen-hour days, trying to make the test kits as quickly as possible. For a diagnostic test to be properly validated, virus samples from an actual patient are required, but the Chinese refused to provide them. A human sample wasn’t available until the first reported case in Washington State, on January 21, and then it had to be isolated and propagated in a special lab, which took until February 12. By then, the German test had been distributed to seventy laboratories around the world.
