Over-the-counter rapid COVID-19 tests are starting to appear in Bay Area drugstores.
Abbott’s BinaxNOW test is now available for about $23.99 for a set of two test kits at some Walgreens and CVS locations and provides test results in 15 minutes, with no need to send samples to a lab or consult a doctor.
“It’s a testing kit, it’s pretty straightforward to use,” said Dr. Dr. Gigi Gronvall, Associate Professor at Johns Hopkins Bloomberg School of Medicine and leader of their COVID-19 testing toolkit website, which has been tracking information about all of the available testing services during the pandemic.
Dr. Gronvall says she took the test herself and found the instructions to be very clear and simple to follow.
“There’s a control band, so that shows you if the test is working. And if there is an additional band, it shows you that you are positive for COVID,” she explained. “It looks a lot like a pregnancy test… it’s very clear what the answer is.”
There have been some concerns about the accuracy of rapid tests, which use a different testing technology than the PCR lab tests that people may have become accustomed to.
“There’s no amplification step. So when you take a swab from your nose, there’s no step where they make lots and lots of copies to see a very faint signal,” Dr. Gronvall explained.
That means that rapid tests are not as effective at detecting cases where patients may not have a large amount of virus in their system.
But Dr. Gronvall cited a recent study in nursing homes that showed a strong correlation between PCR tests and rapid tests, and says they are effective at detecting when people are the most infectious.
“Usually you have to have a lot of virus in your nose to be able to see it in one of these rapid antigen tests, but that’s kind of when you really need to know that you’re infected anyway. Because if you have a lot of virus in your nose, that means you’re breathing a lot of virus out into the air and other people can get infected.”
Abbott says it intentionally packaged each box with two kits so that people can test themselves about three days apart.
Dr. Gronvall says that while the tests may not be as sensitive as PCR tests, they make up for by giving nearly immediate results.
“Convenience is a big part of that and getting a result when it matters most, and that’s the great thing about these rapid antigen tests because you get an answer very quickly.”
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