COVID testing FAQs: Your guide to home, over-the-counter antigen and molecular test kits

• CDC recommends testing five days after COVID exposure
• Four free rapid tests available to all households via USPS
• Molecular tests more accurate, expensive than antigen tests

Assuming you can get your hands on a COVID-19 home test kit — they’ve been in high demand, thanks to the omicron variant — you probably have questions.

Am I testing too early or late? Is this brand or type of test accurate? How do I report my results?

Keep reading to find out the answers to these and all your other testing inquiries.

Don’t see the answer you’re looking for? Send your question to lindsey.leake@tcpalm.com.

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When should I get tested for COVID? 

Five is the magic number, per the Centers for Disease Control and Prevention.

You should get tested five days after exposure, whether you’re symptomatic or not. Quarantine guidelines vary based on vaccination status, but the five-day testing rule is consistent.

Day zero is your most recent contact with an infected person. For example, if you find out Tuesday the friend you had brunch with on Sunday has the virus, get tested on Friday, five days after the last time you saw them. Even if your results are negative, watch for symptoms for another five days and get tested again right away if they develop in that time.

If you’ve had COVID-19 in the last 90 days and are exposed, the CDC advises testing within 10 days if you develop symptoms.

If you’re showing symptoms but are unaware of having been exposed, get tested as soon as possible.

Do COVID tests have age restrictions?

When purchasing an over-the-counter (OTC) test, make sure its age restrictions match your needs.  

For example, the iHealth test has received emergency use authorization from the Food and Drug Administration for adult-collected nasal swab samples in children as young as 2, and for self-collected samples in people 15 and older. The Amazon collection kit is only for adults 18 and older.

If you suspect your child under 2 has been exposed to COVID-19, speak with your pediatrician about appropriate testing options.

What is a rapid/antigen COVID test?

Antigen tests detect SARS-CoV-2 proteins. They’re called “rapid” because they deliver a result within about 15 minutes.

These tests can be taken virtually anywhere: home, work, school, in transit. They’re also relatively cheap, available at retail pharmacies for as little as $8.

Low price isn’t necessarily an indicator of poor quality. At Walgreens, for example, the Flowflex kit costs $9.99, while the QuickVue kit costs $23.99 — because the former contains a single test and the latter comes with two.

A disadvantage of antigen tests is they’re less sensitive than molecular tests. In other words, it’s not uncommon to get a false negative result.

What matters is obtaining the soonest available test, particularly if you’re symptomatic, said Dr. Kami Kim of the University of South Florida Morsani College of Medicine. “Better to know and try to behave responsibly.”

The FDA had authorized 14 at-home, OTC antigen tests and three prescription tests as of Jan. 21.

What is a molecular/NAAT COVID test?

Molecular tests, which pinpoint the virus’ genetic material, are the gold standard in diagnosing COVID-19. 

However, it can take several days to receive a diagnosis. That’s because — even if you collect a nasal swab or saliva sample at home — molecular tests usually require processing in a certified clinical laboratory. 

Molecular tests are more expensive too. The DxTerity kit is $85 at Walmart, while the Pixel by Labcorp kit is $124.99 at CVS Pharmacy. Molecular tests sold in bulk can be in the ballpark of $1,000.

You also may see them marketed as NAAT or PCR tests. The former is short for nucleic acid amplification test. A polymerase chain reaction is one way a clinician can perform a NAAT test; not all molecular tests use PCR.

Molecular tests are reliable for confirmatory testing, according to the CDC. Meaning, if you have COVID-19 symptoms but get a negative result from an antigen test, a molecular test can determine whether that was a false negative.

As of Jan. 21, the FDA had authorized three at-home, OTC molecular tests and one prescription test.

What is an antibody/serology COVID test?

Molecular and antigen tests are viral, diagnostic tests, because they detect a current SARS-CoV-2 infection. 

You may have heard about antibody, or serology, tests, especially early on in the pandemic. They detect past infection. When faced with a virus, your immune system generates proteins called antibodies to combat it, a process that takes one to three weeks, according to the CDC.

If you thought you’d had an undiagnosed, asymptomatic case of COVID-19, an antibody test could determine if you’d been recently infected.

There’s a reason you probably haven’t heard as much about antibody testing in the last year: vaccines. They, too, cause your immune system to develop antibodies.

About 73% of Floridians 5 and older had been at least partially vaccinated through Jan. 20, Department of Health records show. The majority of the state’s residents have antibodies, whether or not they’ve been infected.

Some serology tests can determine whether particular antibodies are vaccine-induced or a result of natural immunity from previous infection. Visit floridahealthcovid19.gov/testing-sites to find a laboratory near you that offers this service.

Will an at-home COVID test identify variants?

Don’t count on a home test identifying variants.

Pharmaceutical companies, such as Abbott, which manufactures the BinaxNOW antigen test, may advertise their tests aren’t affected by SARS-CoV-2 variants. Meaning, if you’ve contracted delta or omicron, for example, the test still will yield a positive result — not that it will indicate which variant you have.

In general, OTC antigen tests feature merely a control line, which indicates whether the test is working properly, and a test line, whose appearance indicates a positive. Unless you have a CDC-contracted genomic surveillance lab in your garage, you won’t know which variant you may have.

If you collect a molecular test sample at home and submit it for processing, the lab is capable of identifying variants, but not every sample is so sequenced. Labcorp, for example, explicitly says variant information is not included in patient reports.

How do I report my COVID test results?

Your test kit likely instructs you to download a free smartphone app that will walk you through the testing process and automatically submit your results to the health department. If not, report your results to your local DOH office, said Renay Rouse, spokesperson for the DOH-Martin office.

Is my at-home COVID test legitimate?

Scammers are selling fake OTC tests online, warns the Federal Trade Commission. Purchase tests only from trusted retailers, and check the FDA database of molecular and antigen tests to make sure yours is authorized for at-home use.

File complaints at reportfraud.ftc.gov.

How can I get a free COVID test?

The Postal Service has teamed up with the Department of Health and Human Services to provide four free, OTC antigen tests to each household in America.

Register at covidtests.gov. Scroll down and click “Insurance Reimbursement for At-Home Tests” to learn how your insurance company will pay for up to eight tests per month per person.

Health department offices, county governments, urgent care centers, community clinics and other health organizations offer free or low-cost, on-site testing throughout the state. Some distribute OTC tests.

Find a location near you at floridahealthcovid19.gov/testing-sites.

Lindsey Leake is TCPalm’s health, welfare and social justice reporter. She has a master’s in journalism and digital storytelling from American University, a bachelor’s from Princeton and is a science writing graduate student at Johns Hopkins. Follow her on Twitter @NewsyLindsey, Facebook @LindseyMLeake and Instagram @newsylindsey. Call her at 772-529-5378 or email her at lindsey.leake@tcpalm.com.