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COVID-19 is the illness that’s caused by the novel coronavirus, SARS-CoV-2. While COVID-19 is mild to moderate most of the time, it can also cause severe illness.

There are a variety of tests that can detect COVID-19. Viral tests, like molecular and antigen tests, can detect a current infection. Meanwhile, antibody tests can determine if you’ve previously contracted the novel coronavirus.

Below, we’ll break down each type of COVID-19 test in greater detail. We’ll look at how they’re done, when you can expect results, and how accurate they are. Keep reading to learn more.

The molecular test for COVID-19 is used to help diagnose a current infection with the novel coronavirus. You may also see this type of test referred to as a:

  • reverse transcription polymerase chain reaction (RT-PCR) test
  • nucleic acid amplification test (NAAT)
  • reverse transcription loop-mediated isothermal amplification (RT-LAMP) test

How is the test done?

Molecular tests use specific probes to detect the presence of the genetic material of the novel coronavirus. To improve accuracy, many molecular tests can detect multiple viral genes instead of just one.

Most molecular tests collect a sample using a nasal or throat swab. Additionally, some types of molecular tests can be performed on a saliva sample that’s collected by asking you to spit into a tube.

You can receive a molecular test at many locations, including, but not limited to:

  • hospitals
  • urgent care centers
  • health clinics
  • pharmacies
  • community-based COVID-19 testing sites
  • at home

When can I expect my results?

Turnaround time can vary for molecular tests. For example, results can be received in 15 to 45 minutes using some point-of care tests. When samples need to be sent to a lab, it may take 1 to 3 days to receive a result.

How accurate is this test?

The molecular test is considered to be the “gold standard” for diagnosing COVID-19. For example, a 2021 Cochrane review found that molecular tests diagnosed 95.1 percent of instances of COVID-19 correctly.

Because of this, a positive result on a molecular test is often enough to diagnose COVID-19, particularly if you also have COVID-19 symptoms. The test typically doesn’t need to be repeated after you receive your result.

It’s possible that you could receive a false-negative result on a molecular test. Aside from errors in sample collection, transport, or processing, timing can play an important role.

  • Testing too early: It can take up to 5 days after exposure before the virus’s genetic material can be detected, so you may receive a false-negative result if you get tested within this window.
  • Testing too late: Viral genetic material in the upper respiratory tract begins to decline after the first week of illness. Because of this, getting tested late can also potentially give a false-negative result.

Because of these factors, it’s vital to seek testing as soon as you begin experiencing COVID-19 symptoms.

How much does it cost?

The Families First Coronavirus Response Act (FFCRA) currently ensures access to free testing for COVID-19, regardless of insurance status. This includes molecular tests. The actual cost for a molecular test is estimated to be between $75 to $100.

Similar to the molecular test, the antigen test can be used to determine if you currently have COVID-19. It’s possible that you’ll also see this type of test referred to as a COVID-19 rapid test.

How is the test done?

An antigen test works by looking for specific viral markers called antigens. If novel coronavirus antigens are detected, the antibodies used in the antigen test will bind to them, producing a positive result.

Samples for an antigen test are collected using a nasal swab. You can receive an antigen test at a variety of places, like:

  • hospitals
  • urgent care centers
  • health clinics
  • pharmacies
  • community-based COVID-19 testing sites
  • at home

When can I expect my results?

The turnaround time for an antigen test is typically quicker than a molecular test. It can take around 15 to 30 minutes to get your result.

How accurate is this test?

Antigen tests are less accurate than molecular tests. The same 2021 Cochrane review discussed above found that antigen tests correctly identified COVID-19 in 72 percent and 58 percent of people with and without COVID-19 symptoms, respectively.

While a positive result is typically quite accurate, false negative results can still happen for similar reasons to molecular tests, like if an antigen test is taken too soon after contracting the novel coronavirus.

Because antigen tests have a lower accuracy, a molecular test may be needed to confirm a negative result, particularly if you currently have symptoms of COVID-19.

How much does it cost?

Like the molecular test, the antigen test is currently free regardless of insurance status under the FFCRA. The actual cost of an antigen test is estimated to be between $5 to $50.

Antibody tests can help to determine if you’ve previously had COVID-19. You can also see this type of test called a serology test or a serological test.

How is the test done?

Antibody tests look for antibodies specific to the novel coronavirus in your blood. Antibodies are proteins that your immune system makes in response to infections or vaccinations.

It takes 1 to 3 weeks for your body to begin producing antibodies. Because of this, unlike the two viral tests discussed above, antibody tests can’t help to diagnose a current infection with the novel coronavirus.

Locations where you can receive an antibody test include:

  • hospitals
  • urgent care centers
  • health clinics
  • pharmacies
  • at home

A blood sample for the test can be collected from a vein in your arm or through a fingerstick.

When can I expect my results?

The turnaround times for antibody tests vary. Some point-of-care facilities may provide same-day results. If a sample is sent to a lab for analysis, you can expect to receive your results in about 1 to 3 days.

How accurate is this test?

A different 2021 Cochrane review looked at the accuracy of antibody tests for COVID-19. Generally speaking, the accuracy of the test increased as time passed. For example, the test was:

  • 30 percent accurate 1 week after symptoms developed
  • 70 percent accurate 2 weeks after symptoms developed
  • more than 90 percent accurate 3 weeks after symptoms developed

We’re still learning about exactly how long antibodies from a natural SARS-CoV-2 infection last. Some research has found that antibodies can persist for at least 5 to 7 months in people who’ve recovered from COVID-19.

How much does it cost?

Like molecular and antigen tests, antibody tests are also covered under the FFCRA. The actual cost of the antibody test is estimated to be between $30 and $50.

A variety of COVID-19 home testing options are now available, including molecular, antigen, and antibody tests. There are two different types of home COVID-19 testing:

  • Home collection: In this type of test, you collect the sample at home and then send it away to a lab to be analyzed. You’ll be contacted when your results are available.
  • At-home tests: At-home tests allow you to collect a sample and then test it at home with a provided testing kit.

The type of sample collected can depend on the type of test as well as the manufacturer. Home viral tests may ask for a nasal swab or saliva sample. Home antibody tests ask you to provide a blood sample from a fingerstick.

Home COVID-19 tests are available with or without a prescription at a pharmacy, retail store, or online. While some insurance plans may cover them, you may be responsible for some costs, so be sure to check with your insurance provider.

Now that we’ve discussed each type of COVID-19 test, let’s look at when to get tested and why.

Viral tests

Viral tests include molecular and antigen tests. They help to detect if you currently have COVID-19.

According to the Centers for Disease Control and Prevention (CDC), testing for current COVID-19 is recommended in the following scenarios:

  • Symptoms: If you currently have symptoms of COVID-19, it’s important to seek testing, regardless of your vaccination status.
  • Exposure: Seek testing if you’ve recently had close contact with someone with confirmed COVID-19. This is defined as being within 6 feet for 15 minutes or more in a 24-hour period. Exceptions to this are:
    • individuals that are fully vaccinated and have no COVID-19 symptoms
    • people who’ve tested positive and recovered from COVID-19 in the past 3 months
  • Risk activities: Unvaccinated individuals who’ve participated in activities that carry an increased risk of exposure to the novel coronavirus should consider testing. Examples include:
    • attending a large event or gathering
    • being in a space that’s very crowded or has poor ventilation
    • traveling
  • International travel: Current guidelines require all individuals that’ve been abroad, including those that’ve been fully vaccinated, to get tested 3 days prior to air travel back to the United States.
  • Referral: In some cases, your healthcare professional or local health department may request that you seek COVID-19 testing.

Viral tests are important in determining if you currently have the novel coronavirus and need to isolate at home. This is vital in helping to prevent the spread of SARS-CoV-2 within the community.

Antibody tests

You may wish to take an antibody test to see if you’ve previously contracted the novel coronavirus. A healthcare professional can advise you on whether an antibody test is recommended.

While antibody tests can tell you if you’ve previously contracted SARS-CoV-2, they can’t determine your level of immunity. This is because it’s currently unclear how long natural immunity to the novel coronavirus lasts.

For this reason, it’s important not to rely on an antibody test to gauge whether or not you’re protected from contracting the novel coronavirus. Regardless of your result, it’s still vital to continue to take everyday steps to prevent COVID-19.

Antibody tests are also a useful epidemiological tool. Public health officials can use them to determine the level of exposure communities have had to the novel coronavirus.

There are a few different tests for COVID-19. These include viral tests and antibody tests.

Viral tests are used to see if you currently have COVID-19. The two different types of viral tests are molecular and antigen tests. Of the two, the molecular test is more accurate.

Antibody tests can determine if you’ve previously contracted the novel coronavirus. But they can’t detect current COVID-19 illness.

All COVID-19 tests are currently free under the Families First Coronavirus Response Act. If you have any questions or concerns about COVID-19 testing or your test results, don’t hesitate to reach out to your healthcare professional.