PARENT SESSION
Wednesday, August 9, 8:00-11:30 am
COS 54 - Disease ecology III: host-pathogen interactions and disease dynamics
L-5, L-6, L-7, Lobby Level, Cook Convention Center
Presiders: S Hall
Neutral networks in influenza dynamics and evolution.
Koelle, Katia*,1, 2, Cobey, Sarah1, Grenfell, Bryan2, Pascual, Mercedes1, 1 University of Michigan, Ann Arbor, Ann Arbor, MI2 Penn State University, University Park, PA
ABSTRACT- The convergence of ecological and evolutionary timescales has been a topic of recent interest in understanding the population dynamics of interacting species. Unarguably, host-pathogen systems are among the clearest examples for which we need to consider this convergence. Disease dynamics are known to influence strain diversity through selection pressures for evasion of the host's immune system; conversely, strain diversity affects disease dynamics through cross-immunity and the resulting competition for susceptible hosts. Thus, immunity and strain cross-immunity play critical roles in driving both infectious disease dynamics and pathogen evolution. Here, I will present a model linking disease dynamics to the evolutionary dynamics of influenza. The model differs from previous approaches by modeling cross-immunity between strains as a function of differences in their antigenic phenotype instead of their amino acid sequences. Central to the proposed model is a genotype-to-phenotype mapping, based on the concept of neutral networks, that cannot be captured by the traditional assumption that cross-immunity is a function of genotype distances. The proposed model recovers known characteristics of influenza evolution and dynamics, including the virus' punctuated antigenic changes, gradual genetic changes, limited diversity, and seasonal outbreaks with higher attack rates during cluster transition years.
Key words: influenza, disease, dynamics