Response to Comments on Kämmerer, et al. (2023) regarding RT-PCR Testing

Franchi and Tomsic (2023) correctly note that our review (Kämmerer et al., 2023) “has a clear focus on the technical aspect of RT-PCR, which is only one piece of the COVID-19 puzzle” and they ask for a more comprehensive discussion beyond our focus on the laboratory assay. They point to the lack of a specific definition of COVID-19 disease and conclude that, in order to test the first and the second of Koch’s postulates, there must be both a purified germ and a specified disease, neither of which was available for COVID-19. In reply, we address two questions they did not ask: 1. Are clinical symptoms induced by SARS-CoV-2 corroborated by RT-PCR? 2. Are Koch’s postulates valid for viruses? We assert that testing asymptomatic people is useless, whereas testing patients with clinical symptoms for a respiratory disease may enable a physician to confirm or reject a suspected diagnosis. Determining a diagnosis for any given patient is the physician’s challenge, while the researcher is responsible to show that the available tools are as near optimal as possible and to clarify the limitations of any such tools. Because there are no tools suitable for comprehensive and exclusive detection of infectious pathogens, we need to proceed carefully in applying the limited tools that do exist for tracing and tracking viral pathogens, to avoid under- or over-estimating a real or suspected pandemic.