[Robert Koch was right. Towards a new interpretation of tuberculin therapy]

At the centenary of Robert Koch's Nobel Prize award, tuberculosis treatment with tuberculin, which was announced in Berlin in 1890, is still considered a failure. Nevertheless, there is now sufficient information supporting the idea that tuberculin therapy was widely used until the second half of the twentieth century; thus, the impact of this treatment should be studied and related to the decrease in tuberculosis-related mortality recorded in that period. Moreover, tuberculin therapy has inspired at least two new immunotherapies; these, however, were directed toward precisely the opposite effect: suppression of the Koch phenomenon. Thus, inoculation of Mycobacterium vaccae polarizes the immune response towards the Th1 type; and inoculation of RUTI avoids local immunodepression after short-term chemotherapy without inducing toxicity. For this reason, Robert Koch's work on antituberculosis therapy should be reread and proper recognition given to his contribution in this field.