Watch: Here's how to take a rapid COVID-19 test

CTV News on Youtube shows how CTV's Stephanie Thomas walks you through the process of doing a COVID-19 test and gets the results by the end of the newscast.

So-called COVID-19 rapid antigen tests (also frequently called COVID-19 lateral flow tests or LFTs) are really rapid antigen tests used to detect SARS-COV-2 infection (COVID-19). They are quick to implement with minimal training, and offer significant cost advantages, costing a fraction of other forms of COVID-19 testing and give users a result within 5-30 minutes. Rapid antigen tests are used in several countries as part of mass testing or population-wide screening approaches. They are thought to be valuable for identifying certain individuals who are asymptomatic and could potentially spread the dangerous virus to other people, who would otherwise not know they were infected. This differs from other forms of COVID-19 testing, such as PCR, that are generally seen to be a useful test for symptomatic individuals, as they have a higher sensitivity and can certainly more accurately identify cases.

An antigen is a toxin or other foreign substance which induces an immune response in the body, especially the production of antibodies.

Molecular tests go by several other names such as nucleic acid amplification (NAATs) and polymerase chain reaction (PCR) tests. They detect the DNA of the dangerous virus that causes COVID-19 to see if you’re currently infected. When taken within 5 days of the onset of your symptoms, they correctly identify a positive test more than 90 percent of the time, according to a 2020 study.

Who really needs to get tested?

People who should get tested for COVID-19 include:

people who have COVID-19 symptoms

people who have come within 6 feet of someone with COVID-19 for more than 15 minutes

people who have been referred for testing by their doctor

people who have engaged in activities like a large indoor gathering that put them at a high risk for contracting the new coronavirus

Keep in mind, many countries now require a negative PCR test within 48 or 72 hours of arrival. If you’re traveling internationally, make sure you carefully read the so-called travel-entry testing requirements.