Even with three available vaccines, COVID-19 is running rampant throughout the U.S. and testing remains essential to preventing the spread of the virus. But things have changed since the early days of spring 2020, when tests were scarce and results took between three and four days to reach patients (if they were informed at all). These days, people have the option to pick up an FDA-approved test at their local Sam’s Club or drug store and swab themselves at home, receiving a result within minutes. While these kits allow for more accessible testing and provide patients with information that could inform the rest of their day—Is it safe for me to go to work today without spreading this virus?—the contexts in which people should rely on these tests vary. VICE consulted with an expert to get a sense of the current home test situation.
What are at-home COVID tests?
There are two types of tests people can take at home: a self-collection kit or a self-test. A self-collection kit requires a person to collect a sample at home (i.e., stick that swab up your own nose) and mail it to a testing center, which will then process the results and let you know within a day or so. A self-test is one where the user swabs themselves at home and gets results within minutes.
The Food and Drug Administration has issued emergency-use authorizations for a number of prescription and nonprescription self-collection kits and self-tests. Self-collection kits, like the empowerDX COVID-19 Home Collection Kit, have you mail in the sample you collected at home yourself; a lab then performs a polymerase chain reaction (PCR) test on the sample. Tests that are done entirely at home, like the BinaxNOW COVID-19 Antigen Self Test, require you to test yourself; 15 minutes later, you’ll have a result. These rapid, on-the-spot at-home tests are called antigen tests.
How are antigen self-tests different from PCR tests?
Antigen tests detect viral particles, while PCR tests pick up the coronavirus’ genetic material. PCR tests are the gold standard as far as testing goes, James Zehnder, a professor of pathology and medicine at Stanford Medicine, told VICE. “That’s the best testing,” he said. “But I think it’s good to have alternatives because not everyone has access to those tests.” A PCR test is more accurate and will be able to pick up a positive infection on day one of symptoms, or early on in your infection even if you’re asymptomatic, while an antigen test may not return a positive result until day two or three of symptomatic cases, Zehnder said.
Antigen self-tests (meaning you’re collecting the sample yourself and testing at home and not mailing your sample to a lab for a PCR test) are not as accurate as PCR tests; you’re more likely to get a false negative with these kinds of tests. “The issue with [antigen] tests is that because they’re not as sensitive, it depends on where you are in the course of your infection,” Zehnder said. “The test is less sensitive, so the window for detecting infection is somewhat narrower.” Because antigen tests are less accurate, the self-test kits will include multiple test swabs and instruct you to test yourself twice within a three-day period to ensure you’re not getting a false negative because you’re testing too early before the virus has built up in your system.
In the event that you get two different test results with an antigen self-test, find a testing clinic and get a PCR test to confirm.
PCR tests are highly accurate, so a kit where you’re mailing in a sample to be tested this way will be more reliable, but slower to return results.
Where can I buy at-home COVID tests?
Self-collection PCR tests:
The kits are in high demand, so call a drugstore ahead of time to see if they’re in stock, or order them online. Make sure you’re only purchasing products that mention they’ve been approved for emergency use by the FDA on the box or online product description.
And keep in mind that some tests may not be covered by insurance, so you should double-check on the drugstore or manufacturer website product listing. If you’re choosing to purchase an at-home test, know you’re taking on an extra expense since COVID tests at clinics and sites are free nationwide.
Who should use at-home COVID tests?
The preferred choice for testing is a PCR test at a medical facility or testing site, Zehnder said. But if you’re short on time or can’t make it to a testing center, there are situations where you can use at-home tests, according to the CDC.
Use antigen tests IF:
- You’re vaccinated and have COVID symptoms.
- You’re unvaccinated and have COVID symptoms. (In that case, get tested immediately.)
- You’re unvaccinated and do not have COVID symptoms and have been exposed to someone with COVID.
Do NOT use antigen tests and instead seek out a PCR test IF:
- You’re vaccinated and do not have COVID symptoms and have not been exposed to anyone with COVID. “If you’re vaccinated and you’re asymptomatic, there’s no reason to get tested unless you’ve been exposed to somebody with COVID,” Zehnder said. “There should be a reason for doing the test.” Even if you’re trying to be considerate before meeting a cousin’s new baby, the best home option would be to try a self-collection kit to mail in, which will be far more accurate.
- You’re vaccinated and do not have COVID symptoms and have been exposed to someone with COVID. Fully vaccinated people who have been exposed to COVID-19 should wait three-to-five days before getting tested at a testing center or doctor’s office.
In short, at-home antigen tests are a good option for people who are symptomatic or know they have been exposed to COVID-19, Zehnder said. They’re not so good if you’re asymptomatic.
When is an at-home test the best option for me?
People who don't have easy access to a testing center can order a self-test or self-collection kit online and get it shipped to their home, allowing for folks in remote or rural areas or who can’t easily travel to get tested without hopping in the car. Home tests can also be helpful for people who live someplace where testing centers are really backed up. Meanwhile, people who meet the criteria above and who are looking for results within minutes may opt for antigen self-tests. For example, if you can’t afford to take off a shift from work to find a testing site and wait for results, an at-home antigen test will deliver results within a few minutes. If you test positive, you know to stay home. But if you test negative the first time, it doesn’t necessarily mean you’re in the clear, so you should still wear a mask and keep your distance from others until you’ve tested negative again.
How do I perform a home COVID test?
Each kit will have different instructions, so read them thoroughly before you start. The number one way to ensure you get an accurate result is to closely follow the test kit’s instructions when collecting your sample. Depending on the test, you’ll either need to swab your nose or collect saliva.
Be sure to wash your hands and sanitize the table, countertop, or surface where you’re opening the kit before you start.
For a test like BinaxNOW COVID-19 Antigen Self Test, open the test card, drop the testing solution into the appropriate slot, swab your nostril, place the swab into the solution, and wait 15 minutes for the result.
Test-by-mail specimens should be shipped the same day you collect your sample.
I tested positive—now what?
If you get a positive result from either a test-by-mail or rapid antigen at-home test, you’re most likely infected. The CDC recommends informing a healthcare provider or local health department if your self-test results come back positive. Other healthcare providers may tell you to visit a testing site for a PCR test, Zehnder said. If your self-test has an app, report your positive result there, too. Isolate and tell your close contacts you’ve tested positive for COVID-19.
I tested negative—am I good to go?
People who received two negative antigen test results or one negative test-by-mail PCR result should feel confident they don’t have COVID-19 and can go to work or interact with others. (Remember: antigen tests come with more than one test that you administer over a couple of days to ensure you’re not getting a false negative.)
According to the CDC, even those with symptoms who correctly followed the self-test directions and got a negative result can rest assured they don’t have COVID-19. (It could just be that cold that seemingly everyone has come down with this summer.)
But should I really trust the results?
It depends. If you lost your sense of smell and have a fever and a cough and got two negative results on an at-home test, it could be a false negative, Zehnder said, so you should behave as if you’re infected and get a PCR test at a medical facility or other site. If your self-test comes back positive, either contact your town or city’s department of health or your physician who can tell you either to self-isolate or get another test.
At the end of the day, Zehnder said you should approach testing based on your circumstance. “If you’re not exposed to a lot of people and you’re working at home and you don't have contacts outside your family, you have to use common sense if you’re fully vaccinated,” noting that breakthrough cases among vaccinated people remain rare.
The bottom line is, at-home antigen tests are pretty good for telling symptomatic people if they’re infected with COVID-19. And that you can trust.
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