Infection processes can in many cases be viewed from a macroscopic perspective, i.e. as being an interplay of different constituents that are present in large numbers. In such cases, differential equations represent the adequate mathematical modeling approach and allow exploring solutions by analytical and numerical methods. The current project will start from differential equation models of various infection scenarios, such as: (i) comparing strategies of clearance versus tolerance of pathogens in the context of sepsis, (ii) modeling antibiotic treatment and resistance development in microbial communities, and (iii) identifiying optimized treatment protocols of immunoglobulin substituion for patients with primary immune deficiency agammaglobulinemia. The biomathematical modeling will include analytically and/or numerically solving differential equations - including analyses of the stability of solutions and the identifiablitiy of parameters - and may by extended to computer simulations of state-based models where appropriate.