Most importantly, which test is the most accurate?
You need to get tested for COVID-19. Maybe your work requires it, or you found out someone you had close contact with has tested positive. Before you rush to the nearest testing site, you need to decide which test is right for you. When it comes to COVID-19 tests, there are a few options to choose from.
Diagnostic COVID-19 Tests: Are You Infected?
By now, you’ve probably heard a number of terms when it comes to tests. There are two main categories: diagnostic (or viral) tests, and antibody tests. A diagnostic test shows if you are currently infected with the COVID-19 virus. There are two types of diagnostic tests:
- PCR test: This test works by detecting the genetic material of the virus. It’s also known as a molecular test.
- Antigen test: This test looks for antigens (proteins on the surface of cells) of the virus that causes COVID-19. Rapid tests are often antigen tests.
Antibody COVID-19 Tests: Were You Infected in the Past?
An antibody test (or serological test) looks for antibodies to COVID-19. These are substances that your immune system makes in response to a threat, such as COVID-19. Antibodies help fight infections, but they can also linger in your body to prevent you from getting the same infection in the future. (In other words, they provide immunity.)
If you have COVID-19 antibodies in your body, that means you have had COVID-19 in the past. That’s the purpose of the COVID-19 antibody test. Note that antibody tests should not be used as a diagnostic test for COVID-19.
How the Test is Taken
There are a few different ways the technician might administer a COVID-19 test. They include:
- Nasopharyngeal (the part of the throat behind the nose)
- Nasal or throat swab (most tests)
- Saliva (a few tests)
- Finger stick or blood draw (antibody tests only)
How Long It Takes
It might seem like you have to wait forever to get your results back, but nowadays, you can get results in 24 to 72 hours. In some cases, it’s as quick as 30 minutes, and these are called “rapid” tests. Most rapid tests are antigen tests, but rapid PCR tests are available.
The average timeline for each test is as follows:
- PCR: A few days or up to a week, but occasionally on the same day
- Antigen: Often very quick, such as in 30 minutes
- Antibody: Up to 3 days, but occasionally on the same day
When to Test & What to Do
It is recommended you get tested for COVID-19 five to 10 days after potential exposure. If you test yourself too soon, you run the risk of getting a false negative because the virus hasn’t had a chance to manifest in your body. (Learn more about what a negative COVID-19 test means here.)
You can also get tested every couple of weeks if you have a job that requires you to be around other individuals. If you test positive, isolate immediately and call your doctor so you can come up with a home care plan that is right for you. (Learn more about what a positive COVID-19 test means here.)
Tamara Moise, MD, is an emergency medicine physician at Big Apple Medical Urgent Care.Preeti Parikh
Preeti Parikh, MD serves as the Chief Medical Officer of HealthiNation. She is a board-certified pediatrician practicing at Westside Pediatrics, is an Assistant Clinical Professor at the Mount Sinai School of Medicine, and is an American Academy of Pediatrics spokesperson. She holds degrees from Columbia University and Rutgers Robert Wood Johnson Medical School and has completed post-graduate training at the Mount Sinai School of Medicine.
- Test for Past Infection. Atlanta, GA: Centers for Disease Control, 2021. (Accessed March 16, 2021)
- Test for Current Infection (Viral Test). Atlanta, GA: Centers for Disease Control, 2021. (Accessed March 16, 2021)
- Coronavirus Disease 2019 Testing Basics U.S.Silver Spring, MD: Food & Drug Administration, 2020. (Accessed March 16, 2021)