Praised by a majority of French people for its speed of results, self-tests to detect Covid-19 have a limit in certain situations.
Maybe you did one just before Christmas? As the end of the year holidays approach, the French have flocked to pharmacies to buy one of the grails allowing them to spend time with their loved ones in all serenity: antigenic tests also called self-tests to detect the Covi-19. And there have been so many purchases of these rapid tests that 58% of pharmacies in France are currently in short supply, according to figures from the Union of dispensing pharmacists’ unions (USPO).
Fortunately, supermarkets have been authorized to market them since Tuesday, December 28, for a period of one month. But did you know that there are certain situations where your test result may turn out to be a false negative?
If the self-test has expired
As with any product, antigen tests have an expiration date. And generally, this is between six months and a year after the date of manufacture. To find out what is happening with your product, you can find these two dates on the packaging.
If the self-test experiences a change in temperature
Each antigen test consists of a reactive solution present in a small vial. For the latter to be effective, it must be at room temperature when performing the test. If not, the result will be skewed. You should therefore not store your self-test in a refrigerator or near a radiator.
If you are infected with the Omicron variant
In an official press release published this Tuesday, December 28, the US Medicines Agency warned of the low sensitivity of this type of test to the Omicron variant. The health agency therefore recommends carrying out a PCR test if “A person tests negative with an antigen test, but is suspected of having Covid-19, for example having symptoms or a high probability of infection from exposure”.