Corona rapid tests have an expiry date. For good reason: “The antibodies used to detect the virus in the rapid corona tests can become weaker over time, so the results may not be reliable,” explains microbiologist Dr. Daniel Rhoads from the Cleveland Clinic in the USA.
For example, the liquid in the test bottle could evaporate over time. And: “The test contains SARS-CoV-2-specific antibodies, which the test relies on to be reliable,” explains Dr. Rhoads. “These antibodies can go bad over time. They are small pieces of protein that can break down over time.”
Expiry dates for corona tests have been extended
But, “The expiration date listed on the packaging may not be the actual expiration date,” explains Rhoads. When manufacturers first brought rapid corona tests onto the market, conservative expiry dates were printed to be on the safe side. New studies have now shown that the expiry date can be pushed back in many cases. On the website of the US Food and Drug Administration (FDA). (Food and Drug Administration) you can check which tests this concerns: The name of the manufacturer, the name of the test and any extended expiry dates are listed there. In some cases, you can compare the lot numbers from the package of a home test against this list. In many tests, the expiry date was extended between 15 and 22 months. Some of these tests are also available in Germany.
Does an expired test show a false result?
If the test has actually expired, it is entirely possible that it will show a false negative result – so you can have Covid-19 even though the test shows a negative result. “If the antibodies no longer work as well, the test may no longer detect the virus as well as when it was originally created,” explains Rhoads. It is not possible for the test to show a false-positive result the other way around. If the corona test is positive, you can usually assume that you have been infected.
Store rapid corona tests correctly
Rapid tests, like medications, should be stored in a cool, dry place. It is best to store the tests in the original packaging. The bathroom is not a suitable place for this: The high humidity can cause corona tests and medicines to be damaged and expire more quickly.
