Types of Tests
There are different types of tests – diagnostic tests and antibody tests.
Diagnostic tests can show if you have an active COVID-19 infection and need to take steps to quarantine or isolate yourself from others. Molecular and antigen tests are types of diagnostic tests than can detect if you have an active COVID-19 infection. Samples for diagnostic tests are typically collected with a nasal or throat swab, or saliva collected by spitting into a tube.
Antibody tests look for antibodies in your immune system produced in response to SARS-CoV-2, the virus that causes COVID-19. Antibody tests should not be used to diagnose an active COVID-19 infection. Antibodies can take several days or weeks to develop after you have an infection and may stay in your blood for several weeks or more after recovery. Samples for antibody tests are typically blood from a finger stick, or blood drawn by your doctor or other medical personnel.
If you are tested, you should quarantine and isolate yourself at home until you receive your test results and follow the advice of your health care provider or a public health professional.
When should I get a test?
- If you have symptoms of COVID-19, even after vaccination
- If you have had close contact (within 6 feet for a total of 15 minutes or more) with someone with confirmed COVID-19, even after vaccination
- If you took part in activities that put you at higher risk for COVID-19 because you could not socially distance as needed, such as travel, attending large social or mass gatherings, or being in crowded indoor settings
- If you have been asked or referred to get tested by your health care provider, or localExternal Link Disclaimer or state health department
Your school, workplace or community may also establish a screening program, in which they test individuals who are part of a group (at work, at school) even if there is no reason to suspect those individuals are infected with COVID-19. The FDA issued more information about screening programs in this fact sheet.
To find a local testing site, you should contact your health care provider or go to your state or localExternal Link Disclaimer health department’s website.
Do COVID-19 tests check for the omicron, delta and other variants?
Currently, COVID-19 tests are designed and authorized to check broadly for the SARS-CoV-2 virus and not for specific variants, sometimes called SARS-CoV-2 viral mutations or genetic mutations. It is common for all viruses to change and mutate over time, resulting in different virus strains. There are no authorized COVID-19 tests that specifically report the presence of the SARS-CoV-2 omicron, delta, or other variants, in patient samples.
The FDA’s SARS-CoV-2 Viral Mutations: Impact on COVID-19 Tests webpage provides technical information about certain COVID-19 tests for which the FDA has identified potential impacts on performance due to SARS-CoV-2 viral mutations. The FDA works closely with test developers to identify potential impacts of viral mutations on FDA authorized COVID-19 tests and help ensure there is minimal impact on test performance when new variants arise.
Local, state, and federal public health agencies, including the Centers for Disease Control and Prevention (CDC), track the SARS-CoV-2 viral variants so we can understand which strains of the virus are spreading. These public health agencies use a test called whole genome sequencing to check for virus strains circulating in the community overall and not for each person.
Health care providers treat patients who have COVID-19 based on the patient’s diagnosis and symptoms and not based on the strain of virus. For more information on treatment options see Know Your Treatment Options for COVID-19 and discuss your symptoms with a health care provider.
Ordering a Test
Many tests, including some home collection and at-home tests, require a prescription or order from a health care provider.
Prescription Tests – Health care providers can determine whether you need a test, and ensure you get the most appropriate test and that you know what the results mean.
For example, certain tests are authorized only for people suspected of having COVID-19 or for people with COVID-19 symptoms that started within a certain number of days. A health care provider can help determine which test is best for your situation. Prescription-only home collection and at-home tests may require you to answer some questions online so that a health care provider can determine whether to prescribe or order a specific test.
Non-Prescription Tests – Some tests are available without a prescription. Home collection and at-home tests available without a prescription may be called “direct-to-consumer” (DTC) or “over-the-counter” (OTC). DTC and OTC tests may be available to purchase at a pharmacy or online, but they may not be available everywhere.
Home Collection and At-Home Tests
Can I get an at-home test? What is the difference between home collection and at-home tests? What kit do I need to order? To answer these questions, it is important to understand the differences in COVID-19 tests, and home collection tests versus at-home tests.
Why is this important? These differences determine where the sample is collected, where the test is processed, and how quickly you find out the results. While at-home tests may be the quickest and most convenient option, they may not be the most appropriate for all situations.
If you want to be sure the test you are buying is authorized by the FDA, visit our tables of molecular, antigen, and serology and adaptive immune response in vitro diagnostic emergency use authorizations (EUA) for more information.
Using the search box in the EUA tables you can use keywords to search and filter the type of test or collection kit you are looking for. Using this search, as new tests are authorized for use, consumers can access up-to-date information on authorized tests and collection kits.
Swab samples use a swab (similar to a long Q-Tip) to collect a sample from the nose or throat. The types of samples include:
- Anterior Nares (Nasal) – takes a sample from just inside the nostrils
- Mid-turbinate – takes a sample from further up inside the nose
- Nasopharyngeal – takes a sample from deep inside the nose, reaching the back of the throat
- Oropharyngeal – takes a sample from the middle part of the throat (pharynx) just beyond the mouth
Saliva samples are collected by spitting into a tube rather than using a nose or throat swab.
Blood samples are only used to test for antibodies and not to diagnose COVID-19. Venous blood samples are typically collected at a doctor’s office or clinic. Some antibody tests use blood from a finger stick.