You are the great hope in the pandemic: Corona rapid tests. Above all, risk patients should be protected with this method. But how safe are the tests? Because at the moment more and more manufacturers are entering the market. There are hardly any independent controls.
“Test, test, test” is the motto in the fight against the corona pandemic. However, the PCR tests that have been tried and tested to date are time-consuming; after a throat swab, the sample is taken to the laboratory. Several days then pass before a result is available. This cumbersome procedure can be shortened with antigen rapid tests. They are considered a tool that could restore as much normality as possible even without a vaccine, because they promise quick certainty when it comes to the important question: Am I positive or negative?
The rapid antigen tests have even been part of the National test strategy. Because, especially in nursing homes, during air travel or major events such as football matches, they could bring security within 15 minutes. Provided they work.
As with the conventional laboratory test, a throat swab is also taken with the corona rapid test. It is soaked in a nutrient solution, which is then placed on a test strip. While the infection is detected on the genetic makeup of the virus in the laboratory test, the antigen test examines the sample to certain proteins. If these are present, the test strip shows the result after a few minutes – similar to a pregnancy test.
The manufacturers promise high sensitivity, i.e. high detectability in the event of an infection. But there are still breakdowns. For example, Tesla boss Elon Musk informed the world on Twitter after his visit to Brandenburg: “Two tests came back positive, two tests negative.” And moderator Jan Böhmermann also reported in his podcast of contradicting test results among his employees. So how reliable are rapid tests really?
On offer: cuddly toys and corona rapid tests
The Federal Institute for Drugs and Medical Devices (BfArM) now lists more than 200 rapid tests on his website. However, in addition to manufacturers and distributors with extensive experience in the medical field, many new and even listed non-specialist. A company actually produces workwear for various industries. Another was busy cleaning tankers and containers before the Corona crisis, another actually sells cuddly toys – and now also quick tests.
What at first glance looks like a list of officially tested and officially approved rapid tests is in reality more of a “market overview”, as stated in the Corona Test Ordinance. To get on the list, manufacturers or importers only need a short one questionnaire Fill out the form that the Paul Ehrlich Institute (PEI) created in cooperation with the Robert Koch Institute (RKI). These are information on minimum standards that the product must meet, for example for sensitivity or specificity. The BfArM only compares the manufacturer’s information with these minimum criteria. If they are met on paper, the product is listed.
Rapid tests are therefore not tested by an independent body before they come onto the market. There is no time for that, said Health Minister Jens Spahn at the federal press conference last week. “To do it quickly, we first had to rely on the manufacturer’s information.”
According to the ministry, the procedure is based on the currently applicable European and national rules for placing in vitro diagnostics on the market, which include antigen tests. Unlike pharmaceuticals, medical devices are in principle not subject to any official control, explains a BfArM spokesman when asked by ntv.de.
Criticism of dealing with antigen tests
But Timo Ulrichs sees this as a danger, especially in the context of the Corona crisis. “If more and more providers are pushing their way onto the market, this should be treated with extreme caution,” says the epidemiologist in an interview with ntv.de. That is partly dubious. Such a relaxed approach to testing could have serious consequences. “People rely on the result. If the rapid tests then do not have sufficient sensitivity or specificity, that is absolutely not conducive to our current situation.” In the worst case, they would unconsciously infect other people, the expert criticizes the lax standards.
The opposition in the Bundestag has already expressed criticism of the handling of the rapid tests. Achim Kessler, health policy spokesman for the Left, told Bayerischer Rundfunk that the federal government had missed out on scientifically sound checking of rapid antigen tests. He proposes to require manufacturers shall furnish within three months of approval meaningful studies on their efficacy and safety.
In the meantime, seven antigen tests that are available on the market have examined by a research team led by virologist Christian Drosten from the Berlin Charité for their reliability. Among other things, the scientists checked the specificity of the tests – i.e. their susceptibility to false-positive results. Six tests performed well, one a little worse:
- Coris Bioconcept Covid-19 Ag Respi-Strip: 100 percent
- RapiGEN Biocredet Covid-19 Ag: 100 percent
- Abbott Panbio Covid-19 Ag Rapid Test: 99.26 percent
- Nal of Minden Nadal Covid-19 Ag test: 99.26 percent
- Roche / SD biosensor Sars-CoV-2 Rapid Antigen Test: 98.53 percent
- R-Biopharm Rida Quick Sars-CoV-2 antigen: 94.85 percent
- Seaweed Coronavirus Ag Rapid Test Cassette: 88.24 percent
Drosten and his team see great potential in the use of rapid tests. “The immediate availability of test results could enable novel health concepts,” says the study. Epidemiologist Ulrichs also recognizes clear advantages of antigen tests – provided they have been scientifically tested. “If, for example, a patient is admitted to hospital with unclear symptoms, they can be taken to the right ward with the help of a rapid test,” he explains. That not only protects the other patients, but also the hospital staff.
An approval of the antigen tests for home use after the Model of the USA Ulrichs sees it critically, however. “The important thing is that you always have these tests done by a professional,” says the expert. Because even with actually reliable rapid tests, a false-negative result can occur if the throat swab is not carried out properly.