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NJIT Mathematical Biology Seminar

Tuesday, October 24, 2006, 4:00pm
Cullimore Hall 611
New Jersey Institute of Technology

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Multi-strain disease models with antibody-dependent enhancement

Lora Billings

Department of Mathematical Sciences
Montclair State University

As we become more sophisticated in our resources to fight disease, pathogens become more resilient in their means to survive. Antibody-dependent enhancement (ADE), a phenomenon in which viral replication is increased rather than decreased by immune sera, has been observed in vitro for a large number of viruses of public health importance, including flaviviruses, coronaviruses, and retroviruses. This increased viral growth rate is thought to increase the infectivity of the secondary infectious class. We study the complex dynamics induced by ADE in multi-strain disease models. In the models, ADE induces the onset of oscillations without external forcing. We derive approximations of the ADE parameter needed to induce oscillations and analyze the associated bifurcations that separate the types of oscillations. We investigate the stability of these dynamics by adding stochastic perturbations to the model. We also present a preliminary analysis of the effect of vaccination strategies. Though the models presented are specifically designed for dengue hemorrhagic fever, our results are applicable to any epidemiological system in which partial immunity increases pathogen replication rates.