At-home COVID-19 tests allow you to collect your sample and detect active COVID-19 infections.
But what if you have at-home COVID-19 tests nearing expiration or expired on your shelf?
Matthew Binnicker, Ph.D., director of the Clinical Virology Laboratory at Mayo Clinic, says companies set the original test dates arbitrarily due to these diagnostic at-home tests being developed rapidly. So, check your boxes before you toss them.
“Now that we are 3 1/2 years into the pandemic, those manufacturers have had the opportunity to go back and assess the test performance over prolonged periods of time. And they’ve updated the expiration dates in many cases,” says Dr. Binnicker.
His first recommendation if you have tests at home is to search the Food and Drug Administration (FDA) website for information on updated expiration dates.
“If you take a test that is beyond the expiration date, and the test is positive, that’s likely a reliable result, especially if you have a respiratory illness. If you get a negative result from a test that is beyond the expiration date, I’d recommend making sure the test doesn’t have an extended expiration date. And if it’s beyond that, then definitely go out and get another test or go in and have a healthcare provider collect a swab for a lab-based test before you rule out COVID-19,” Dr. Binnicker says.
Can at-home tests detect current strains of COVID-19?
“Yes, they should detect the currently circulating strains of COVID-19. The good news is that most of the changes in the virus with these new variants are in the spike protein, which is the part of the virus that binds to the cells. And the protein these antigen tests are looking for is a different protein where not as many mutations occur. So that allows us to confidently say that these tests should pick up the circulating strains,” says Dr. Binnicker.
Testing positive
Are you contagious if you test positive for COVID-19? Most likely, says Dr. Binnicker.
“When an at-home antigen test is positive, it means that that person is still shedding or excreting a high amount of viral protein. In most cases, that means that the person is shedding a high amount of virus, and likely a high amount of virus that could be spread from one person to another,” he says.
He says if you get a positive at-home antigen test, consider yourself at risk of spreading the virus to others.
Testing negative
Dr. Binnicker says testing at home is recommended if you experience COVID-19 symptoms. If it comes back positive, you likely have a COVID-19 infection. But what if you have symptoms and the test comes back negative?
“If your test comes back negative at home, and you still have those typical symptoms of COVID-19 — sore throat, cough, fever, body aches — that’s when I’m recommending that people go in to see their healthcare provider, get a swab collected that can be sent to a lab for a PCR-based test. That will give us the most reliable information on whether you truly have, or don’t have, COVID-19,” says Dr. Binnicker.
