As a result, I don’t think home testing is as useful as some have hoped. If used on a large scale to screen for covid, they could send millions of anxious people looking for lab tests and medical attention they don’t need.
As the covid-19 pandemic spread around the world last year, economists and scientists called for a massive expansion of testing and contact tracing in the United States, to find and isolate those infected. But the number of daily tests in the United States has never greatly exceeded 2 million, according to the Covid Tracking project, and most of these were performed in laboratories or on special instruments.
Home tests will now be made in the tens of millions, their makers say, but some experts are not sure even tests that have worked perfectly would be able to change the picture of the pandemic much at this point. “The real value of these tests dates back six months,” says Amitabh Chandra, a professor at the Kennedy School at Harvard University. “I think the switch to over-the-counter products is great, but it has limited value in a world where vaccines are becoming more widely available.” Vaccination documents may be more important for travel and meals than test results.
The companies selling the tests say it is still a good strategy to get back to normalcy, especially since children are not yet getting vaccinated. For employers who want to keep an office or factory open, they say, self-directed consumer testing might be a good option. An Abbott spokesperson told me they could also help people “start thinking about coordinating more covid-aware bridal showers, baby showers, or birthdays.”
The UK government began giving out covid antigen tests free of charge, by mail and at street corners, on April 9, saying it wanted people to “make a habit” of testing themselves twice a week when social distancing restrictions are relaxed. Along with vaccines, free tests are part of this nation’s plan to eliminate the virus. Later, however, a leaked government memo stated hHealth officials privately worried about a tsunami of false positives.
In the United States, there is still no national campaign around home testing or a grant for them, and as a direct expense, they are still too expensive for most people to use with any frequency. Maybe it’s for the best, given my experience.
Types of tests
The three tests we tried included two antigen tests, BinaxNow from Abbott Laboratories and a kit from Ellume, as well as a molecular test, called Lucira. In general, molecular tests, which detect the genes of the coronavirus, are more reliable than antigen tests, which detect the presence of the outer envelope of the virus.
Everything you need is in one box, except for the Ellume test, which must be paired with an app. Overall, the Lucira test featured the best combination of accuracy and simplicity advertised, but it was also the most expensive at $ 55.
We haven’t tried Quidel QuickVue, another antigen test, or a molecular test from Cue Health. These tests, although authorized for home use, are not yet sold directly to the public.
After trying all the tests, I don’t plan to invest in their regular use. I work from home and don’t socialize, so I don’t really need to. Instead, I plan to keep at least one test in my closet so that if I feel bad or lose my sense of smell, I can quickly tell if it’s covid-19. The ability to perform tests at home may become more important next winter when cold and flu season returns.
BinaxNow by Abbott
Required time: About 20 minutes
Price: $ 23.99 for two
Availability: In some CVS stores from April. Abbott says he performs tens of millions of BinaxNow tests per month.
Precision: 84.6% for detection of covid-19 infections, 98.5% for correct identification of negative covid-19
It’s the home version of the 15-minute quick test that the White House used last year to screen staff and visitors. It is an antigen test, which means it examines a sample of a nasal swab for a protein in the shell of the virus. It went on sale in the US last week and I was able to purchase a two-test kit from CVS for $ 23.99 plus tax.
The technology used is called “lateral flow immunoassay”. Simply put, it means It works like a pregnancy test. It is basically a paper card with a test strip. As the sample passes through it, it encounters antibodies that stick to the viral protein and then to a colored marker. If the virus is present, a pink bar appears on the test strip.
I found the test quite easy to perform. You use a dropper to dispense six drops of the chemical into a small hole in the card; then you insert a cotton swab after passing it through both nostrils. Rotate the swab counterclockwise, bend the card to bring the test strip into contact with the swab, and that’s it. Fifteen minutes later, a positive result will appear as a faint pink line.
The downside to testing is that there is room for two different types of user error. It is difficult to see the drops coming out of the dropper, and using too little could cause a false negative. You could therefore rub your nose incorrectly. Unlike the other tests, this one cannot tell if you made a mistake.
And in addition to the prospect of user error, the test itself has some accuracy issues. BinaxNow is the cheapest test, but it is also the most likely to be wrong, missing about one in seven true infections. Abbott cautions that the results “should be treated as assumptions” and “do not exclude the SARS-Cov-2 ”.
But a buyer won’t find the rate accurately without delving into the fine print. The company is also burying a crucial requirement imposed by regulators: To compensate for any less accuracy, you are supposed to use the two tests in the kit, at least 36 hours apart. I doubt that a casual buyer realizes this. The requirement of two tests is hardly mentioned in the instructions.