FDA authorizes 1st COVID-19 antigen test, which produces results within minutes

The Food and Drug Administration has authorized emergency use of the first antigen coronavirus test, which produces results within minutes and is relatively cheap to make, according to the agency.

The tests, developed by Quidel Corp. of San Diego, is the third type of test to be authorized by the FDA.

At the moment, there are two types of commercially available tests: PCR-based tests diagnose currently infected people using genetic material in saliva or mucus, and antibody tests that detect prior infections using blood samples.

Like PCR-based tests, antigen tests can detect an active infection, but use a nasal or throat swab to detect viral proteins expressed on the outer surface of the coronavirus. An antigen is a term for a foreign substance, like a virus or bacteria, while an antibody is a protein created by the body in response to a previous infection.

MORE: Antigen versus antibody testing for COVID-19

Dr. Deborah Birx, the White House coronavirus response coordinator, said she believes implementing effective antigen testing can help Americans reopen the country safely.

"There will never be the ability on a nucleic acid test to do 300 million tests a day or to test everybody before they go to work or to school," she said. "But there might be with the antigen test."

Yet antigen tests are less accurate than antibody and PCR tests, and the World Health Organization cautioned that further research should be done before the tests are used widely.

While the tests produce highly accurate positive results, there is also a higher chance they produce false negatives than PCR tests. The FDA said a negative results from an antigen test does not rule out an infection and may need to be confirmed with a PCR test.

The FDA said that it expects to authorize more antigen tests in the future.

Despite a massive effort, the nation faces "truly daunting" challenges to deploy millions of coronavirus tests to safely re-open the economy, the head of the National Institutes of Health told lawmakers Thursday.

NIH Director Francis Collins told the Senate Health, Education, Labor and Pensions committee that government and private industry have launched a $2.5 billion, taxpayer-funded effort to develop, manufacture and distribute technology capable of accurately testing millions of people a week by the end of the summer or the fall, before the annual flu season.

Widespread availability of testing is seen as critical to reopening the economy because it would allow public health officials to identify and contain a rebound of the virus. It remains a high bar to clear.

"I must tell you, senators, that this is a stretch goal that goes well beyond what most experts think will be possible," Collins said. "I have encountered some stunned expressions when describing these goals and this timetable to knowledgeable individuals. The scientific and logistical challenges are truly daunting."

The Associated Press and ABC News contributed to this report.