Introduction Antibodies and antigens interact in order to trap the offending microbe generate an immune reponse in secondary lymphoid organs Kinetics of antigen-antibody interaction antigen excess seen in the start of the infection due to login to view 2 more bullets equivalence antibody production has become adequate and thus login to view 1 more bullet this corresponds to the window period for heptitis B antigen serologic studies antibody excess the infection has resolved and thus login to view 1 more bullet