The sale of self-tests detecting antibodies against the new coronavirus is no longer prohibited in Belgium, announced the Federal Medicines Agency (FAMHP) on Monday.
The Agency warns users for a misinterpretation of the results, however, saying that they could give people a false sense of safety, or cause them unnecessary anxiety, depending on the result.
Self-tests analyse blood from a finger prick and do not require the intervention of a doctor or other health care professional to take the sample or to interpret the result of the test. The tests indicate whether or not a person has developed antibodies against the coronavirus, but cannot determine whether the infection is active or if the person is (still) infectious.
As fake self-tests are circulating on the internet, buying one should be done from a reliable source, such as a pharmacist. Even when bought from a reliable source, however, these tests have a higher risk of giving false-positive or false-negative results.
In March 2020, the sale of self-tests was banned for a period of six months as a precautionary measure, as there were no self-tests on the market compliant with the standards at that time.
The Agency understands that citizens want clarity about their own health as soon as possible, but warns that the results of a self-test could both give a false-negative and a false-positive result.
A positive test result for an antibody self-test does not guarantee that the user has or has had Covid-19, that they are immune, or that they are currently still infections, the agency stressed.
In some cases, the test may give a false-positive result, such as if it did not detect antibodies against the coronavirus, but against another similar virus.
“However, a positive result is an important signal that you cannot ignore,” they added. “Strictly follow precautions: keep your distance, wear a face mask when recommended, and wash your hands regularly with soap and water. Contacting a doctor to have the test result confirmed is also recommended.”
On the other hand, a negative test result does not guarantee that the user does not have or has never had Covid-19, and whether or not they are currently infectious.
A false-negative result could be due to the number of antibodies in the body being too low to detect with this test, which is possible if the infections occurred less than 14 days ago, or if the body produces few antibodies. Additionally, some antibodies only remain in the body for a few months.
The Brussels Times