What are the different types of coronavirus tests?
There are three broad categories of coronavirus tests in the United States Two diagnose whether you have an active infection and a third indicate whether you previously had the virus.
Here’s how they work:
Most tests look for bits of the virus’ genetic material and require a nasal stick to be taken by a healthcare professional and then sent to a laboratory. This is considered the most accurate way to diagnose an infection, but it is not perfect: the cotton swab must be given a good enough sample so that any virus can be detected.
These tests usually take hours to process in the lab, so you probably won’t get results back for at least a day, even if a handful of quick tests take about 15 minutes on the spot. Other genetic tests use saliva instead of a cotton swab.
A newer type of test looks for proteins found on the surface of the coronavirus rather than the virus itself. These antigen tests are just hitting the market, and experts hope they help expand testing and speed up results.
Antigen testing is not as accurate as genetic testing, but is cheaper, faster, and requires less specialized laboratory equipment. They still need a nasal cotton swab by a healthcare professional.
A recently approved test from Abbott Laboratories takes 15 minutes and can be performed in schools, offices and elsewhere.
Antibody tests look for proteins that the body produces to fight infections in a patient’s blood test. Antibodies are a sign that a person previously had COVID-19.
Researchers do not yet know whether antibodies protect humans against another infection or how long the protection can last. So antibody testing is most useful for researchers who measure what part of the population was infected.
AP answers your questions about coronavirus in this series. Submit them to: FactCheck@AP.org.
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