A Simple Model of Pathogen Immune Dynamics Including Specific and Non-Specific Immunity

Department of Mathematics, University of Trento, Via Sommarive 14, Trento 38050, Italy.
Mathematical Biosciences (Impact Factor: 1.3). 06/2008; 214(1-2):73-80. DOI: 10.1016/j.mbs.2008.04.004
Source: PubMed


We present and analyze a model for the dynamics of the interactions between a pathogen and its host's immune response. The model consists of two differential equations, one for pathogen load, the other one for an index of specific immunity. Differently from other simple models in the literature, this model exhibits, according to the hosts' or pathogen's parameter values, or to the initial infection size, a rich repertoire of behaviours: immediate clearing of the pathogen through aspecific immune response; or acute infection followed by clearing of the pathogen through specific immune response; or uncontrolled infections; or acute infection followed by convergence to a stable state of chronic infection; or periodic solutions with intermittent acute infections. The model can also mimic some features of immune response after vaccination. This model could be a basis on which to build epidemic models including immunological features.

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    • "Note that recovery is not explicitly modelled in this system; however, when an individual reaches a B level close to B ∞ , it is effectively immune to further infections and its pathogen load is effectively 0. Other simple models for within-host pathogen–immune interactions have been considered [24] [28] [33] with potentially different behaviours that may be realistic in many cases. For the purpose of this analysis, system (1) describes adequately the dynamics of an acute infection that is eventually cleared by the immune system. "
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