As COVID-19 testing becomes more widely available, people may question whether they should get tested and which test to take. Currently, there are three types of tests. Two are diagnostic, which means they can detect active infection through a nasal or throat swab, or saliva or sputum. The third is a blood antibody test that can detect past infection.

The diagnostic tests measure different things. The molecular tests—also referred to as polymerase chain reaction (RT-PCR), nucleic acid amplification test (NAAT), and loop-mediated isothermal amplification (LAMP)—detect viral genetic material, are 95 percent accurate, and take two or three days for results. If you test negative with these tests, you can safely assume you are not infected.

The rapid test, which detects protein fragments shed by the virus, is 80 percent accurate and results are usually available within 15 minutes. If you test positive, you have the infection. However, if your result is negative, it does not necessarily mean you are not infected. The reasons for this are twofold. One, the test only indicates the virus at a single point in time and there may not be enough virus for it to register. Two, if the nasal swab doesn’t go far enough up the nose, it may not pick up the virus.

In some places, the molecular test is being offered as a rapid option, combining accuracy with speed. Some testing sites offer a combination COVID-19 molecular test and flu A and B in one nasal swab test, also available within 15 minutes. This allows you to get tested for COVID-19 and the flu at the same time.

Accuracy of the tests depends on several factors. For one, if the infection is more prevalent in your community, there is a greater chance that you may have been exposed and your positive result is accurate.

The blood test detects antibody levels against COVID-19, which serve as markers of early infection, late infection, or both. You should get it between one and three weeks after symptoms have resolved, but you can take it any time, even months, after infection. For those with no symptoms, a blood test is better than a nasal swab since it can indicate past infection. It is presumed that the presence of these antibodies confers immunity, but it is not known how long that protection will last, which means it may be possible to recover from COVID-19 and get re-infected.

Where to Get Tested

Most counties across the United States have drive-through testing centers for the nasal, throat, or sputum test. In addition, many hospitals, health departments, urgent care centers, and even pharmacies such as CVS and Walgreen’s can administer these tests and possibly the blood antibody test. Otherwise, the antibody test is available through your health care provider and commercial labs. Availability and criteria for testing differ by location so it is important to call ahead.  

If you’re experiencing symptoms, such as a dry cough, shortness of breath, or fever, make an appointment for a nasal or throat swab or sputum test. You should also isolate yourself from others until you’ve been symptom free for seven to 10 days to prevent the spread of the virus to other people.

If you have no symptoms but feel you have been exposed (if you’ve recently flown on an airplane, for example) or want to get tested to see if you have had COVID-19, the blood antibody test may be more appropriate.

Know which type of test you are getting. For example, many countries require a negative molecular test for people traveling from abroad. Whether you get a positive or negative result, you should continue to wear a face covering and practice social distancing and good hand hygiene.

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COVID-19 (Coronavirus) and Neurologic Disease Resource Center