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Worried you have COVID ahead of July 4th gatherings? The age of your at-home test is key to its accuracy

The age of your at-home test is key to its accuracy
The age of your at-home test is key to its accuracy 02:33

MIAMI – Home COVID tests can provide a quick and usually accurate result. But one key component to an accurate result is the age of the test kit.

Dr. Aileen Marty, an infectious disease expert, explains when it's time to toss a kit in the can and grab a newer one.

"The FDA forces them to keep up, but that doesn't mean the one on your shelf kept up," said Dr. Marty.

She mentions a signal to swap out for a new kit, besides time, when there's a new variant circulating that could 'overcome immunity.'

"It's very likely to overcome the detectors in your rapid antigen test that's been sitting on the shelves for four months," said Marty.

If you wonder why, she says each of these rapid antigen tests looks for proteins of the virus, but not necessarily the same ones.

So, some variants might slip under older or expired home test kits' radar, "and so you don't necessarily get a result that's truthful," added Marty.

She shares that the federal government's free test kits tend to be more reliable over more variations for longer periods. 

"That one is looking for nucleocapsid, which doesn't change as much as some of the other proteins that some of the other tests look for," said Marty.

Health experts agree that PCR tests are more accurate than rapid antigen tests because they detect small amounts of viral material.

If you're unsure if your at-home test is up-to-date, you can go to a free COVID testing site locally.

"It's going to be a holiday weekend," mentioned Daniel Alcea, waiting in line at the drive-thru testing site at Tropical Park.  "Going to be around people like you said: if you have the testing available, go ahead and use it."

Alcea is one of many we saw at Tropical Park taking an extra step to be safe before heading out of town to celebrate the Fourth of July. 

"It's definitely important going with the family and kids," said Mercedes Ortega.  "So, you want to make sure you're safe and healthy."

And even if you're not testing for COVID, be mindful of high respiratory illness activity in Florida.  CDC data shows Florida's the lone state since May 18th with consistent weekly high activity.

And when it comes to at-home COVID tests, the FDA's website lists the kits and their shelf life.  Of course, as Dr. Marty mentioned, it's essential to factor in new variants when determining when to order a new at-home kit.

And Dr. Marty warns about the strongest subvariant of the omicron strain circulating in the United States, BA.4 and BA.5. She says it evades our immunity easier, as both have significant mutations, making them more contagious.

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