The FDA actually allowed some clinics to use the technique as an experimental method to screen blood donations back in 2016 when the virus started spreading in Puerto Rico. Thanks to that testing period, the FDA was able to prove that the test can indeed effectively and accurately spot the virus. According to additional tests in five external laboratories, its clinical specificity (or the frequency in negative results in uninfected subjects) is 99 percent. Now that it's officially been approved, clinics and hospitals around the country can use it to make sure their blood supply won't infect anyone with the virus.

FDA Center for Biologics Evaluation and Research director Peter Marks said in a statement: