The FDA authorized two new types of diagnostic COVID-19 tests this week, the first antigen test and the first at-home test that uses saliva samples.
An antigen test is a new type of diagnostic test that detects fragments of proteins that are found on or within the virus. It's different from the most commonly used COVID-19 diagnostic test, called a PCR test, which detects the genetic material of the virus.
The FDA granted emergency use authorization May 9 to San Diego-based Quidel Corporation for its COVID-19 antigen test, which the agency said works much faster than other diagnostic tests. The tests, which use samples from patients' nasal cavities, can give results in minutes.
The test's positive results are highly accurate, but there is also a higher chance of false negatives, so negative results may need to be confirmed with a PCR test.
Antigen tests can be made at lower costs than PCR tests and could potentially be scaled up to test millions of Americans per day due to their simpler design.
The FDA said it expects to authorize more antigen tests.
The agency also gave emergency use authorization May 8 to the first at-home diagnostic test that uses saliva samples instead of nasal cavity samples.
The tests were developed by a lab at Rutgers University in New Brunswick, N.J. It uses saliva samples collected by patients using a self-collection kit, which they can return to the Rutgers lab for results.
The tests must be ordered by a physician, according to The New York Times.
Rutgers' saliva test is the only test authorized to use saliva samples. The FDA said Rutgers' data showed the saliva samples were as accurate as nasal cavity swabs, but that it still prefers nasal cavity samples.
The agency also said the saliva tests should be limited to people who have COVID-19 symptoms.
Rutgers has 75,000 saliva test kits ready to ship out and can process 20,000 tests per day with results given to patients within 48 hours, according to the Times.
Andrew Brooks, PhD, chief operating officer and director of the technology department at the Rutgers lab, told the Times the price will be around $100 per test, but that prices will vary.