Antigen Testing Debate As Approval Sought For Faster Coronavirus Testing
The push to “re-open” economies is intensifying the need for more, and faster, testing for Coronavirus.
The tests currently used to see if people are actively infected with the virus are sophisticated molecular tests that can spot its genetic material in specimens swabbed from inside peoples’ noses and throats. Most use the technique known as polymerase chain reaction — PCR — to generate and analyze millions of copies of genetic sequences from the virus.
But those tests require sophisticated equipment, highly trained technicians and complicated processes that use specialized chemicals; those strict requirements of PCR tests, and problems in reliably meeting them, have all contributed to the testing shortage.
Widescale testing is considered crucial for determining the scope of the pandemic, bringing it under control and keeping large new outbreaks from occurring. Testing enables public health authorities to spot new infections quickly so patients can be isolated and so anyone they might have had contact with.
Typically, antigen tests are much easier and less expensive to manufacture and simpler to perform than either PCR tests or antibody tests. The same technology is used in pregnancy tests.
“It looks very much like a pregnancy test. And they’re very simple. They don’t require special chemicals or training to use them. And they can give you a read out in about 15 minutes or so,” says Gehrke, one of the collaborators on the E25BIO test.
Gehrke says his company’s test appears to be very accurate when evaluated with samples of the virus in the lab.
“The difficult question — and the one we want to ask — is how well does it perform on samples from real patients,” Gehrke says.
Papenburg questions whether antigen test could ever be as reliable as the genetic tests because, unlike those PCR tests, they can’t produce large quantities of the target proteins — so might be more likely to miss an infection.