The Food and Drug Administration approved the first rapid test for the novel coronavirus over the weekend. The test, made by the biotechnology company Cepheid, returns results in around 45 minutes and does not need to be processed in a lab.

But the test should primarily be used in emergency rooms and hospitals, not in doctors’ offices, David Persing, chief medical officer of Cepheid, told Stat News. In a hospital, it could help streamline care for sick people — knowing someone has or does not have COVID-19 quickly will let doctors decide how much protective equipment is needed to treat them, for example. “This is not a test for the worried well,” Persing said.

Machines that run the new Cepheid tests are already in some health care facilities in the US. Like the tests already in use at public health labs and hospitals, this new test looks for bits of the virus in patient samples. The company says it will start shipping tests this week.

After a long, costly delay, the US is finally testing tens of thousands of people a week for the novel coronavirus. Those tests, though, require that doctors swab a patient’s nose or throat and send that sample off to a lab with specialized equipment and technicians. At the fastest, turnaround time can take a few hours; in the US today, it’s taking days to receive test results.

Tests that can be run outside of a lab and can give doctors answers quickly are critical in the fight against a fast-spreading pandemic virus like the novel coronavirus. Engineers have the technology for rapid testing, but it’s not as widespread or well-established as the slow methods labs are relying on to test people who suspect they have COVID-19. For example, there are only around 5,000 Cepheid systems in use in the US — the systems that run the standard, slower tests are much more ubiquitous.

Testing, Testing, Testing: We must widely test our population, diagnose mild and even asymptomatic cases. Requires point of care diagnostics in doctor's office. We must advance these immediately to market. It means serology to know who was exposed and developed immunity. 9/n — Scott Gottlieb, MD (@ScottGottliebMD) March 21, 2020

Testing in the US needs to expand even more than it has been, and be done more quickly, in order to bring the pandemic under control. Systems like Cepheid’s that bring tests out of the lab, even though they’re limited, are an important step toward that goal.