  System dynamics and agent based simulation models can both be used to model
and understand interactions of entities within a population. Our modeling work
presented here is concerned with understanding the suitability of the different
types of simulation for the immune system aging problems and comparing their
results. We are trying to answer questions such as: How fit is the immune
system given a certain age? Would an immune boost be of therapeutic value, e.g.
to improve the effectiveness of a simultaneous vaccination? Understanding the
processes of immune system aging and degradation may also help in development
of therapies that reverse some of the damages caused thus improving life
expectancy. Therefore as a first step our research focuses on T cells; major
contributors to immune system functionality. One of the main factors
influencing immune system aging is the output rate of naive T cells. Of further
interest is the number and phenotypical variety of these cells in an
individual, which will be the case study focused on in this paper.
