Seminar Interacting Random Systems
- Wednesday, 27.10.2021, 11:30 (Online Event)
András Tóbiás, TU Berlin:
Virus dynamics in the presence of contact-mediated host dormancy (online talk)
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Abstract: We investigate a stochastic individual-based model for the population dynamics of host-virus systems where the hosts may transition into a dormant state upon contact with virions, thus evading infection. Such a dormancy-based defence mechanism was described in Bautista et al (2015). We first analyse the effect of the dormancy-related model parameters on the probability of invasion of a newly arriving virus into a resident host population. It turns out that the probability of dormancy initiation upon virus contact plays a crucial role, while the lengths of the dormancy periods or the death rate during dormancy are largely irrelevant. Given successful invasion, we then show that the emergence of a persistent virus infection ('epidemic') in the host population corresponds to the existence of a coexistence equilibrium for the deterministic many-particle limit of our model. In this context, all dormancy-related parameters have a significant impact. Indeed, while related systems without recovery of infected individuals and dormancy may exhibit a Hopf bifurcation, giving rise to a variant of the 'paradox of enrichment', we provide simulations and rigorous partial results showing that the inclusion of dormancy and recovery can prevent this loss of stability. Finally, we show that the presence of contact-mediated dormancy enables the host population to maintain higher equilibrium sizes (resp. fitness values) - while still being able to avoid a persistent epidemic - than host populations without this trait, for which high fitness values would imply a high risk for the emergence of a persistent epidemic. This adds a twist to the relevance of 'reproductive trade-offs' usually associated with costly dormancy traits. The subject of this talk is joint work with Jochen Blath.
Seminar Interacting Random Systems (Online Event)
Organisers: Alexandra Quitmann and Alexander Zass