This $5 rapid test is a potential game-changer in COVID-19 testing

Abbott Labs got emergency approval from the US Food and Drug Administration for its rapid antigen test, which can detect a COVID-19 infection in 15 minutes.

The test is a "game changer," according to Brett Giroir, the US assistant secretary for health in the Department of Health and Human Services.

Investors sure think so: Abbott's stock was up about 8% Thursday morning.

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In California, many lockdown rules are still in effect but the good news is that it might be working in the fight against coronavirus. However, access to testing continues to be an issue for many.

The FDA's emergency use authorization is for Abbott's BinaxNOW COVID-19 Ag Card. The size of a credit card, BinaxNOW will cost $5 and will come with a free mobile app that will let people who test negative display a temporary, date-stamped health pass that is renewed each time a new test is taken.

The antigen test, in which involves a nasal swab, uses the same type of technology as a flu test. Abbott says it anticipates producing 50 million BinaxNOW tests a month by October.

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"The massive scale of this test and app will allow tens of millions of people to have access to rapid and reliable testing," said Joseph Petrosino, a professor of virology at Baylor College of Medicine, in a statement released by Abbott.

Petrosino's labs have been leading efforts to provide COVID-19 testing for the college and Harris County, which includes Houston.

"With lab-based tests, you get excellent sensitivity but might have to wait days or longer to get the results. With a rapid antigen test, you get a result right away, getting infectious people off the streets and into quarantine so they don't spread the virus," he said.

The BinaxNOW COVID-19 Ag Card is the fourth antigen test to receive an emergency use authorization from the FDA.

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Antigen tests, which look for pieces of the virus, are not as reliable as traditional Polymerase chain reaction tests, which look for the virus' genetic material. However they are a quicker, less expensive and less invasive. PCR tests have been beset by supply chain problems as well as back-ups at labs which have delayed results and frustrated patients, doctors and public health experts alike.