Some Nebraskans are reaching for over-the-counter COVID tests after returning from trips, before visiting Grandma or after waking up with a scratchy throat or stuffy nose.
The rapid antigen tests, sold in pharmacies, online and in some big box stores, require users to swab their own noses and read results (like they would a pregnancy test) or send the sample to a lab for processing.
On the plus side, they deliver results in as little as 15 minutes, rather than a day or two for PCR tests. And they’re more convenient than going to a drive-thru test site or clinic.
Some scientists, economists and others long have argued that making frequent antigen testing more widely available offers a way to loosen the pandemic’s grip on the nation.
Others, however, note that the tests are less accurate in people who don’t have symptoms. False negatives could result in people unwittingly spreading the virus. And unlike tests conducted at test sites and clinics, the results aren’t automatically reported to local health departments, complicating their efforts to track the virus.
Dr. James Lawler, a co-executive director of the University of Nebraska Medical Center’s Global Center for Health Security, said PCR tests still are the gold standard for testing. Antigen tests could be valuable if someone has symptoms, a quick answer is needed and a PCR test isn’t available.
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But even if enough were available to allow for frequent use, they can give people a false sense of security. “I don’t think the antigen tests are a panacea,” Lawler said.
More of the tests soon will make their way into Americans’ hands.
The Biden administration on Wednesday announced a $1 billion purchase of rapid at-home COVID-19 tests, an additional investment geared toward expanding the availability of such products.
Along with the authorization of another at-home test product, the $1 billion investment and earlier outlays should put the country on track to quadruple rapid testing by December, White House COVID-19 response coordinator Jeff Zients said.
The new supplies will add to a $2 billion investment in rapid testing announced by the White House last month. By December, 200 million rapid tests will be available to Americans each month. The administration also will double to 20,000 the number of sites in the federal government’s free pharmacy testing program.
Meanwhile, Australian test-maker Ellume earlier this week recalled nearly 200,000 test kits because of concerns about a higher-than-expected rate of false positives. According to the New York Times, that represents about 5.6% of the approximately 3.5 million test kits the company has shipped to the United States.
Demand for testing is expected to increase further as a result of the Biden administration’s requirement that all businesses with more than 100 employees either mandate vaccination for their workers or require them to take weekly coronavirus tests.
In some places, the at-home tests have been hard to come by. Because of high demand, both Walgreens and CVS have limited the number of at-home tests customers can buy.
A sign in a midtown Omaha Walgreens last week indicated purchases of over-the-counter COVID-19 test kits were limited to four per transaction.
CVS limits purchases of three kinds of at-home tests to six on CVS.com and four in stores, the company said. The company recently added a fourth at-home test to its lineup of products.
The at-home tests aren’t cheap, while PCR tests typically come at no out-of-pocket costs to consumers. The Abbott BinaxNOW COVID-19 rapid antigen test and Quidel’s QuickVue At-Home OTC COVID-19 test are sold in packages with two tests each, retailing for $24 a box.
Mark McCurdy, a pharmacist and owner of Mark’s Pharmacy in Cambridge said he had 10 kits last week. Word then got out among the town’s 1,000-plus residents, and the kits were gone in two days. “It’s hit or miss when we can get them,” he said.
McCurdy said people want the convenience of doing the tests at home. But lab tests offer more quality controls, eliminating operator error and making sure swabs get checked correctly.
Dr. Tom Safranek, chief medical officer for Omaha’s TotalWellness, said that if someone with symptoms does an at-home test and gets a positive result, “you can take that to the bank, especially if they do it early after the onset of symptoms.”
But if a person with symptoms tests negative, questions may arise on whether they collected the sample correctly or read the results properly, said Safranek, a former Nebraska state epidemiologist. A doctor might order another test, also factoring in a patient’s vaccination status and exposure details.
But a negative test also could mean a person was too early in the course of his or her infection to register on the tests, which are less sensitive than PCR.
Relying on at-home tests, however, effectively results in a person acting as his own doctor, Safranek said. Well-trained clinicians bring experience in determining what tests to use and in interpreting test results that home users may not possess.
“I wouldn’t totally pooh-pooh these things,” he said. “But not everyone will read and appreciate the subtleties.”
Omahan Kate Geiger navigated the ins and outs of home testing just before Labor Day. Two of her children, who unknowingly had been exposed to a friend who had COVID, tested positive with the at-home tests.
“I’m glad that it was available,” she said, “because I feel it was easier for them to test, and we knew to keep them out of school.”
The children’s doctor, in fact, told her there was no need for them to take another test. Geiger’s test, however, was negative. She took a rapid test at a lab the next day and it, too, was negative. On Day 3, she took a PCR test that was positive.
Geiger said she persisted in getting tested even though she was vaccinated because of her exposure to her children and their friend and the fact that she had a lot of symptoms.
Safranek said Nebraska already is using rapid tests in nursing homes. If residents are tested regularly, the tests can pick up a missed infection a couple of days later.
But there can be consequences if the tests are done incorrectly, he said, such as failure to isolate a sick person.
A recent study that compared the BinaxNOW with PCR at four sites in Florida found that antigen test results were more likely to agree with positive PCR tests when viral load was high.
In such cases, the BinaxNOW was positive 75% of the time. That means it missed 25% of infections, said Dr. Lao-Tzu Allan-Blitz, a co-author of the study and resident physician at Brigham and Women’s and Boston Children’s Hospitals.
The test’s sensitivity in that real-world setting also was lower than in the company’s trials, he said.
Ultimately, the tests may not be robust enough to use before heading to a bar or concert, Allan-Blitz said. But taking them repeatedly, particularly in closed settings such as schools, likely would be a better option.
“I think these antigen tests are going to be tools that are best used on a serial basis in certain populations than as a one-off test,” he said.
This report includes material from Bloomberg News.
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