QUICK AND CONVENIENT: Your guide to at-home COVID testing
DULUTH, MN -- With a nationwide surge in COVID cases, many have turned to at-home testing to avoid the lines and long waits of lab-based PCR tests.
At-home antigen tests are affordable, quick and convenient, and health experts say they’ve really broadened testing capacity.
“The antigen tests are kind of a game changer for us,” said Dan Soular, Vice President of Medical Affairs at Grand Itasca Clinic & Hospital, “What they do is they pick up the [antigen proteins] of the COVID virus.”
Antigens are proteins that elicit the body’s immune response.
Antigen tests contain a solution with antibodies already present.
If those antibodies latch on to any antigens present in a swab sample, the solution produces a dye that causes a thin blue line to appear on the test (alongside a control line), indicating a positive result.
According to Soular, detecting antigens isn’t always the most accurate metric.
“You have to have enough of the virus in your system for this test to pick it up, so that’s one of its limitations,” he said.
Most of the time, that occurs when you’re symptomatic.
According to Susan Vitulli, Senior Public Health Educator with St. Louis County, PCR tests are the more reliable option if you’ve been exposed and are asymptomatic.
She said PCR tests can detect much smaller amounts of the virus since they use and replicate genetic material instead of proteins like antigens.
“You have to sort of look at the details of each circumstance. You sort of start with, ‘Am I symptomatic?’ If yes, then do a rapid test. If no, then maybe your best course of action is a PCR,” said Vitulli.
According to Soular and Vitulli, a positive result on an antigen test is a lot more clear-cut than a negative one.
“A positive test on an antigen test at home, you have COVID. A negative test is reassuring, but what we’re recommending in clinic is if you have a negative test and you’re still having symptoms, you should retest 3 to 5 days later,” Soular said.
Current CDC recommendations advise getting tested up to five days after potential exposure, just to make sure the virus has enough time to show up on the test.
Both experts say a PCR test is much more accurate, but antigen tests are a useful tool if you find yourself in a pinch.
Soular said it’s also important to practice other COVID safety measures in order to slow transmission, regardless of test results.
“Getting vaccinated, boosted, wearing a mask, washing your hands... we’re two years into this and [those things] still work very well,” he said.
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