The adaptive vertebrate immune system is a wonder of modern evolution. Under most circumstances, the dynamics of the immune system is well-matched to the dynamics of pathogen growth during a typical infection. Some pathogens, however, have evolved escape mechanisms that interact in subtle ways with the immune system dynamics. In addition, negative interactions the immune system, which has evolved over 400 000 000 years, and vaccination, which has been practiced for only 200 years, are possible. For example, vaccination against the flu can actually increase susceptibility to the flu in the next year. As another example, vaccination against one of the four strains of dengue fever typically increases susceptibility against the other three strains. Immunodominance also arises in the immune system control of nascent tumors--the immune system recognizes only a small subset of the tumor specific antigens, and the rest are free to grow and cause tumor growth.
In this talk, I present a physical theory of original antigenic sin and immunodominance. How localization in the immune system leads to the observed phenomena is discussed.
1) M. W. Deem and H. Y. Lee, ``Sequence Space Localization in the Immune System Response to Vaccination and Disease,'' Phys. Rev. Lett. 91 (2003) 068101.
2) J.-M. Park and M. W. Deem, ``Correlations in the T Cell Response to Altered Peptide Ligands,'' Physica A, to appear.