Unfortunately, in some parts of the country, COVID cases are on the rise once again. Because of this, you may be digging out an at-home COVID test you bought or were sent for free several months ago. Is it still effective? While COVID tests have “use by” dates on the label, in some cases the expiration dates have been extended, making it confusing to figure out how long they are actually good for. Faulty at-home tests could lead to false positives or false negatives, which is why it’s important to know for sure how long your test is good for. Keep reading for everything you need to know.
Do at-home COVID tests expire?
“All lab tests—including home kits and professional lab tests—have an expiration date,” says Dr. Stephen Brecher, PhD the director of microbiology in the Department of Pathology and Laboratory Medicine at VA Boston HealthCare Center. Dr. Brecher says that in certified labs, tests can’t be used past the printed expiration date. “For a home test, the kit may work after the expiration date, but do you want to make a potentially life-altering decision or possibly spread the virus using an expired kit?” he asks, adding that expired tests are more likely to give false negatives than false positives. Dr. Daniel Rhoads, MD, a clinical pathologist affiliated with Cleveland Clinic, says that the reason at-home rapid COVID tests expire is due to the antigens and antibodies involved in the tests. “The test uses an antibody to detect the virus, but that antibody is not stable forever,” he says. Dr. Thomas Russo, MD, the chief of the division of infectious diseases in the department of medicine at the University of Buffalo, echoes this saying that the antibodies may no longer be active in an expired test. Some at-home COVID tests have had their expiration or “use by” date extended after they were put on the market, so if you have an expired at-home test, it’s a good idea to Google it before throwing it out to make sure it’s truly expired. “My understanding of the at-home rapid tests is that what [the U.S. Food and Drug Administration] wanted was ‘real-time data for stability,’” Dr. Russo says. He explains that this is a prediction of how stable the tests are and will be; info to be assessed and updated in the future based on performance over time. Dr. Russo says this is because of how crucially needed the rapid tests were. “Most of the tests that were first released had a shelf life of four to six months, but as time went on, data showed that they were actually good for longer, such as nine, 12, or 15 months,” he says. This led to expiration dates for some tests to be updated.
Can an expired test tell you anything helpful?
If you have an at-home rapid test that’s truly expired (and you Googled the brand to make sure), should you toss it out? You can still give the test a try, but all the experts say that the reliability may be affected. “From a practical standpoint, the FDA is going to tell you not to use an expired test, but if you get a positive result using an expired test, it’s likely a positive result,” Dr. Rhoades says, reiterating what Dr. Brecher said earlier about a false negative being more likely than a false positive. This means that if you get a positive result from an expired home test, you should take the results seriously by self-isolating and seeing a doctor if your symptoms turn problematic. If an expired at-home test comes back negative, this is where the experts say it’s a bit more tricky. Since this is more likely to happen as rapid tests lose their sensitivity, it’s best to get your hands on a non-expired test—or even better a PCR test as they are more accurate. If your test is negative but you have symptoms of COVID, it’s best to assume you do have COVID and self-isolate and see a doctor for severe symptoms.
How to store your at-home COVID tests
Another important factor in maintaining the integrity of your at-home COVID tests is making sure you store them properly. Dr. Waleed Javaid, MD, a professor in the Division of Infectious Diseases in the Department of Medicine at Icahn School of Medicine at Mount Sinai, says the tests should be stored at room temperature. Tests shouldn’t be kept anywhere too cold (like the fridge, freezer, or in a chilly garage if you live somewhere cold) or too hot (like the trunk of your car). “The heat itself may cause the components or compounds in the test to change and UV rays could also have an effect,” Dr. Javaid says. With COVID cases back on the rise, Dr. Javaid says it’s important to be as safe as possible; we’re not out of the woods just yet. At-home rapid tests play a part in this as a tool that can indicate whether it’s safe for you to be around others or not. This is why, Dr. Javaid says, it’s important to use reliable tests. Expired tests are less sensitive which could lead to a feeling of false security, which could ultimately put more people at risk of contracting COVID. If one thing’s for sure, it’s that you don’t want to put your health and safety to the test. Next up, here’s what you need to know about the long-term effects of COVID if you do test positive.
Sources
Dr. Stephen Brecher, PhD, director of microbiology in the Department of Pathology and Laboratory Medicine at VA Boston HealthCare Center; associate professor of pathology and laboratory medicine at Boston University School of MedicineDr. Daniel Rhoads, MD, clinical pathologist affiliated with Cleveland ClinicDr. Thomas Russo, MD, professor and chief of the Division of Infectious Diseases in the Department of Medicine at the University of BuffaloDr. Waleed Javaid, MD, professor in the Division of Infectious Diseases in the Department of Medicine at Icahn School of Medicine at Mount Sinai
