Comparison Covid-19 antigen self-test for the nose

Contents of self-test kits

The first differences begin with the contents of the packaging. The most necessary materials are included in each test kit: test cassette, extraction buffer, sterile swab and instructions for use. However, many amateur testers (this is no different with Profitest) do not have a plastic bag for disposal of the materials used in the package. The only lay tests that show a biosafety bag are the well-known Hotgen and the new test winner Citest Diagnostics lay test. This also has a tube holder included. The buffer solution can be safely placed in it for carrying out the test.

Sensitivity, specificity and overall sensitivity

What you should know: The sensitivity values ​​given in the instructions for use only refer to use with a high virus concentration. So this value says nothing about the accuracy of the rapid test at a medium or low virus concentration. That is why the Paul Ehrlich Institute has published a list of specially tested rapid tests. Here, too, the rapid tests were tested for accuracy at medium (ct>25<30) and low (ct>30) viral loads. The specificity is consistently at a level above 99% in all lay tests that we have compared. The sensitivity given in the package leaflet at high virus concentrations is consistently >95% in all lay tests. An exception here is the layman’s test by Beier Bioengineering, which already stands out negatively here with 77.8%. When comparing the sensitivity at an average virus concentration (ct>25<30), significantly more deviations are already noticeable. According to the measurements of the Paul-Ehrlich Institute, 4 tested amateur tests have a sensitivity of less than 66% or 2/3. These include the lay test from Baier Bioengineering with 0% sensitivity, the Hotgen antigen self-test with 52% sensitivity, the Safecare antigen self-test with 62% sensitivity, and the Joinstar COVID-19 antigen rapid test (Collodial Gold) with 64% accuracy at one medium viral load. The Green Spring lay test and the brand new VivaChek Rapid Gold Pro lay test still perform very well here with a sensitivity of 95%. However, the undisputed winner in this category is the amateur test from Citest Diagnostics, which was able to shine with 100% accuracy in the measurement results. With a low viral load (ct>30), most lay tests detect almost nothing. This also includes the Hotgen lay test, which is probably the most popular lay test on the market. It is therefore all the more important to pay close attention to this value when selecting a suitable self-test. The only lay tests in our comparison that can still reliably detect an infection with a low viral load according to the PEI are:

• the Green Spring lay test with 40% accuracy
• the Vivacheck Rapid Gold Pro amateur test with 94% accuracy
• the Citest Diagnostics antigen lay test with 90% accuracy

Overall sensitivity

The overall sensitivity describes the accuracy of the test over all virus concentrations in total. The Beier test (28%) and the Hotgen amateur test (56%) bring up the rear here. The Safecare lay test (62%) and the Joinstar lay test (64%) come in ahead. The Green Spring amateur test achieves a good result with an overall sensitivity of 86%. The winners in terms of overall sensitivity in our comparison are the Rapid Gold Pro lay test from VivaChek with 92.5% and the lay test from Citest Diagnostics with an overall sensitivity of 98%. With these self-tests, you can undoubtedly assume that they will usually detect any virus infection – provided, of course, that the test is carried out correctly.

Limit of Detection (LoD)

The limit of detection (German: lower detection limit) describes the value from which minimum viral load the rapid test can detect the virus. This value should be as low as possible. Here, most rapid tests range between values ​​of 200-400 TCID/50ml. In our comparison, the rapid tests from Citest Diagnostics (100 TCID/50ml) and the Rapid Gold Pro Ag rapid test from VivaChek with 75.5 TCID/50ml showed particularly low detection limits.

Omicron detection

All quick tests from our comparison passed the bridging test according to the Paul Ehrlich Institute. However, this information must be classified correctly: Even if the test basically detects and can detect omicrons, the Ct values ​​at medium and low concentrations are decisive as to whether the omicron detection also applies to lower viral loads.

Overall Score

In the overall result of our comparative nasal lay test, only 3 of the 7 tests we compared achieved a satisfactory result. The Laintest from Joinstar, Safecare, Hotgen and Beier failed our comparison with a total score of 3 to 6 out of a possible 10 points. In our comparison, the price/performance winner was the new Rapid Gold Pro AG rapid test from VivaChek with 9 out of 10 points. The best overall result, and thus our quality winner, is the Citest Diagnostics COVID-19 Antigen Rapid Test (Nasal Swab) with a total score of 9.5 out of 10 possible points.