You may be wondering about the differences between COVID-19 test types. Which tests can be done at home? What’s required for international travel? How accurate are COVID-19 swab tests for suspected infection? We answer these questions and others below.
When to test for COVID-19
Here are situations when you may want to take a COVID-19 test:
If you think you might have COVID-19
If you have symptoms of COVID-19, getting a COVID-19 test can help you determine if it’s safe for you to be around others or if you need to be treated for COVID-19 or something else.
If you’ve been around people with COVID-19
If you’ve been in close contact with someone who has COVID-19, you should get tested two to three days later, even if you’re not showing symptoms.
When required for travel, work or other events
Different establishments may require proof of vaccination and/or a negative COVID-19 test. Some of the most common situations where testing is needed are:
- Foreign countries requiring COVID-19 testing for travel
- Entertainment venues requiring a negative COVID-19 test to attend events
If you have long-haul symptoms that don’t go away
There is also a COVID-19 antibody (serology) test that can determine if you had COVID-19 in the past. So if you’re experiencing what could be long-haul COVID-19, testing may be used to help determine the cause of your symptoms.
What you need to know about COVID-19 test types
There are several tests that can be used to identify an active infection, as well as one test that looks to see if you’ve had COVID-19 in the past. Here’s a quick overview of the different types of tests:
| PCR test | Antigen test | Rapid PCR test | Antibody (serology) test | |
|---|---|---|---|---|
| Tests for | Active infection | Active infection | Active infection | Past infection |
| How to get tested | At-home test or clinic | At-home test or clinic | Some clinics (limited availability) | Clinic |
| Typical time to get results | 2-4 days | About 20 minutes | About 20 minutes | 1-3 days |
| Accuracy | Generally high | Moderate to high | Moderate to high | Varies |
| Greatest benefit | Best accuracy | At-home test | Quicker than standard PCR | Identify past infection |
Viral testing for active COVID-19 infection
There are a few different types of COVID-19 viral tests that look for active infection. Each type of test has its own advantages and disadvantages.
PCR testing for COVID-19
What it is: A COVID-19 polymerase chain reaction (PCR) test is a molecular test that looks for genetic material related to COVID-19. It’s the gold standard test due to its high accuracy, and it’s the best and earliest way to tell if someone is infected.
PCR tests require special equipment and skilled technicians to run the test. That means it can take up to 5 days to get results back – but it’s usually faster if you get your test done at a health clinic rather than using an at-home kit.
How it’s done: Usually, a swab is inserted into the nose or mouth to get a direct sample of mucous from the nasopharynx, the part of the upper respiratory tract sitting behind the nose and in the throat. Sometimes, PCR tests use a sample of your saliva instead.
PCR tests look for the RNA, or the genetic code of the virus. During the test, your sample goes through a process called amplification that makes it possible to detect even the smallest amount of the coronavirus.
How to get tested: In most cases, the quickest way to get your results is to schedule a COVID-19 test at a health care facility. If you need the results within a certain amount of time – for example, if you’re traveling – it’s best to get your COVID-19 test in person.
There are at-home tests, but it can take longer to get results because you need to send them in through the mail to get processed.
How you’ll get your results: If you get tested in a clinic, your COVID-19 test results will come to you in the same way as other lab results. If you use an at-home kit, check with the supplier for more information about how results are reported.
Antigen test for COVID-19
What it is: The COVID-19 antigen test looks for pieces of protein from the coronavirus. This test is quick and easy, and you’ll have results in less than 20 minutes. However, antigen tests can be less accurate than PCR tests, so they may not meet testing requirements in some situations.
How it’s done: The testing sample is usually from a nasal or throat swab, but it can sometimes be saliva. After applying the sample to a test strip, a colored line may appear, indicating that COVID-19 proteins were detected. If no COVID-19 proteins are detected, a line will not appear.
One catch is that there needs to be a significant amount of the protein for the test to be positive. If you’re at the early stage of the illness, there may not be a lot of these proteins in your nose. So it’s possible to get a false negative result, meaning the test says you don’t have COVID-19 when you actually do.
How to get tested: You can get an antigen COVID-19 test from your health clinic. However, there are also antigen COVID-19 self-tests if you don’t want to go to a clinic. You can find self-tests online and sometimes in retail stores. Some tests to look for are BinaxNOW, QuickVue, Ellume and Flowflex.
How you’ll get your results: If you test through your health clinic, look to get your results in the same way that you get other lab results. You may even be tested and receive results within the same visit.
If you’re doing a self-test and need documentation of a negative COVID-19 result, you’ll use a special testing app on your phone, computer or other device with a camera. During the test a specially trained proctor will provide guidance and watch as you perform the test. When the test is complete, your test result will be stored in the app. Check with your at-home test supplier for more information.
Rapid PCR tests for COVID-19
What is it: Rapid PCR tests differ from traditional COVID-19 PCR testing because technicians can process the rapid test at the clinic, sometimes giving you results within 20 minutes. The advantage is that this test delivers quick results, with greater accuracy than antigen tests. However, accuracy may not be as high as traditional PCR testing.
How it’s done: Rapid PCR tests use a nose swab. Processing is similar to a traditional PCR test but uses a different type of machine.
How to get tested: Availability is limited. At this point, rapid PCR tests are mostly being used at select urgent care clinics and pharmacies.
How you’ll get your results: You can expect to receive your results in the same way you normally get results from your clinic or pharmacy. You may even be tested and receive results within the same visit.
How to tell if you had COVID-19: Testing for past COVID-19 infections
It’s possible to get COVID-19 and recover without getting a COVID-19 test. Perhaps you had a mild case, or no symptoms at all. Or, maybe you knew that you were sick but weren’t sure if you had symptoms of the flu or COVID-19.
In most cases, it’s not necessary to know if you’ve recovered from COVID-19. The exception is if a prior infection could affect your future care. So, your doctor may recommend this type of test if you have long-haul COVID symptoms or if you need a medical procedure and tested positive for COVID-19 in the past.
Antibody test for COVID-19 (serology)
What is it: This test looks for antibodies made by the immune system in response to COVID-19. The presence of antibodies indicates that your immune system has responded to fight off the illness, meaning you had COVID-19 before.
Accuracy: These antibodies show up about 20 days after the initial infection, so it’s possible that you may get a false negative if you test and it’s been less than three weeks since you had COVID-19.
How it’s done: A blood sample is taken by finger prick or from a vein. When the blood is processed, your doctor will be able to see if there are COVID-19 antibodies in your blood.
How to get tested: Talk to your primary care doctor to discuss if should have a COVID-19 antibody test.
How you’ll get your results: You will receive your COVID-19 antibody test results in the same way that you receive your normal lab work.
What does a COVID-19 test cost?
Does insurance cover COVID-19 testing at the clinic?
Most insurance companies cover COVID-19 testing for active infections (PCR and antigen) when performed at a health care clinic or pharmacy.
COVID-19 antibody (serology) testing is usually covered by insurance if ordered by your doctor and is considered medically necessary. If you order your test on your own, it might not be covered.
But insurance coverage varies – it’s always a good idea to check with your provider to see what’s covered for you.
Where can I get a free COVID-19 test for home use?
- Through the federal government. Every household can order two sets of four at-home antigen COVID-19 tests for free through the COVIDtests.gov website. Tests usually ship within 7 to 12 days.
- Through your state. Free at-home COVID-19 PCR tests are available in many states. Minnesota, Michigan and Wisconsin offer free at-home test kits at sayyescovidhometest.org. Iowa also offers free at-home tests.
COVID-19 testing can keep you safe and stop the spread
COVID-19 testing is a valuable tool in our battle against COVID-19.