Christoph's Interview & Publication

What inspired your research, and what did it cover?
Prof. Winfried März, Head of the SYNLAB Academy, led the COVAG (Corona Virus Antigen) study and the investigation of COVID-19 antigen tests by comparing them with RT-PCR. At the beginning of 2021, the German national testing strategy was aimed at identifying all individuals infected with SARS-CoV-2, and due to their speed and low cost, antigen tests became increasingly important. However, antigen tests were only validated by the manufacturer and not yet in real-life scenarios. We, therefore, organised a study in the largest test centre in Stuttgart to investigate the diagnostic performance of antigen tests in a real-life scenario with more than 2000 participants. Each individual was tested with two antigen tests and one PCR test as a reference. From autumn 2021 to spring 2022 we continued the study as new variants emerged.

Looking at the potential of your findings, what difference can they make?
We found that the sensitivity of the antigen tests was lower than stated by the manufacturers, and that the results were less reliable for asymptomatic patients and patients with higher Ct values. We also found that the predominant alpha variant was detected with significantly lower sensitivity than the wild type. These findings give realistic values from a real-life study and can change the way we interpret antigen test results. In addition, we showed that antigen tests should be validated for every virus variant separately.