From when to test to how to get one, here's what to know about COVID-19 testing kits

Free COVID-19 test kits are available to American households via the United States Postal Service.

People can expect to see different testing brands arrive in their mail. The Biden administration announced contracts with three major manufacturers to supply the first wave of free home tests — Abbott Laboratories, iHealth Lab and Roche Diagnostics. The Food and Drug Administration has granted emergency use authorization to a dozen home test manufacturers.

Here's what you need to know:

When should I test?

The omicron variant moves faster than previous variants, but that doesn't mean you'll test positive the day after exposure.

Dr. Katie Sharff, chief of Infectious Disease for Kaiser Permanente Northwest, recommends people wait three to five days after an exposure to test. The at-home tests are often most accurate when the individual is displaying symptoms.

Before I use the at-home test, is there anything I should do?

Experts are encouraging test recipients to read all the instructions of their tests before beginning them to be sure the results are as accurate as possible. Test kits should be kept out of extreme temperatures and thrown away when they are expired.

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What's the difference between a PCR and a rapid antigen (at-home) test?

"The rapid antigen tests detect COVID when people have a high amount of viral particles, whereas the PCR test is an amplification process," Sharff said. "So PCR tests are much more sensitive. A rapid antigen test is going to detect the viral particles if someone has a high amount of virus and is shedding a lot of virus."

She added that rapid tests, the tests you use at home, are most sensitive when you're symptomatic, even more so if you've had symptoms for a day or two. If someone is asymptotic and therefore isn't shedding as much of the virus, it's harder for a rapid test to detect.

"For someone who's asymptomatic, a rapid antigen test I think of as a coin flip, like 50/50, it may or may not pick up your disease," Sharff said. "They're really best used in individuals who are symptomatic."

How do I get a rapid test?

Free COVID-19 tests from the federal government can still be ordered online at special.usps.com/testkits. Orders will ship within seven to 12 days of ordering, according to covidtests.gov.

That's in addition to the eight at-home coronavirus tests Americans with health insurance can get each month for free.

These tests will either be free directly at the point of sale, if your health plan provides for direct coverage, or by reimbursement if you are charged for your test. People seeking reimbursement should keep their receipt if they need to submit a claim to their insurance company.

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Even if your health coverage plan has set up a network of preferred providers where you can get a test with no out-of-pocket expense, you can still get tests from other retailers outside that network.

Insurance companies are required to reimburse you at a rate of up to $12 per individual test (or the cost of the test, if less than $12). More information about this is available at cms.gov/how-to-get-your-at-home-OTC-COVID-19-test-for-free.

People without insurance can also get free at-home tests from some community health centers.

How reliable are rapid test results?

Is a positive rapid test considered a 'true positive'?

Yes. In previous waves, people have been encouraged to confirm their positive rapid test with a PCR test. However, with the current variant being as widespread and infectious as it is, this is no longer the case.

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"If you have a positive rapid antigen test, you should consider it a true positive and you do not need a confirmatory PCR test," Sharff said.

Is a negative rapid test considered a 'true negative'?

At-home rapid tests usually come in packs of two. Sharff said it's best to take the second test 48 to 72 hours after the first. She added that a negative at-home rapid antigen test represents just a "moment in time" when a person was not shedding enough virus to be detected.

"I would think of it as one more tool in your toolkit to ensure protection," Sharff said. "Other tools in your toolkit, of course, are vaccines, which is the best protection against COVID, (and) masking with a well-fitted high-grade mask if you have availability of an N95 or KN95. If you have a negative antigen test at the time you go visit grandpa, (you're) less likely to be infected with COVID, with omicron, but the tests aren't perfect, especially in asymptomatic individuals."

She added that if you have symptoms but a negative antigen test, you likely still have COVID-19. She recommended people with symptoms isolate regardless of their result and retest in a couple days.

What should I do if I test positive?

The main thing people should do if they test positive is to isolate from others.

The Centers for Disease Control and Prevention changed its recommendations around quarantining after a positive test result from 10 days to five days.

Davis warned that people with the virus should evaluate whether they still have symptoms before going back into the public, regardless of whether they have passed the five-day window.

Where can I get a PCR test?

Marion County is offering free walk-in PCR testing and vaccinations from noon to 7 p.m. Mondays through Saturdays and 11 a.m. to 4 p.m. Sundays at the Oregon State Fairgrounds Pavilion on Sunnyview Road just east of 17th Street.

No insurance is required. All three vaccines are available including booster and pediatric doses.

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A free Woodburn mass testing event is being held from 10 a.m. to 3 p.m. Saturday, Jan. 29 at Centennial Park, 900 Parr Road. It is free for all ages, regardless of immigration status. No ID or doctor's note is required. Walk-ins are welcome.

Santiam Hospital and Clinic in Stayton is offering tests from noon to 6 p.m. Monday through Friday in the back parking lot of Foothills Church, 975 Fern Ridge Road SE. Appointments are required. To schedule an appointment, go to labdash.net or call 503-769-3230.

USA Today reporters Jim Sergent and Ariana Torrey contributed to this report. Contact reporter Tatiana Parafiniuk-Talesnick at Tatiana@registerguard.com or 541-521-7512, and follow her on Twitter @TatianaSophiaPT.

This article originally appeared on Register-Guard: Your free COVID-19 test kits are coming. Here's what you need to know