2025/07/07 by Marco Seiler, Seiler, Marco
Immunology and Microbiology · Medicine · #60K35 #FOS: Mathematics #HIV Research and Treatment #Influenza Virus Research Studies #Probability (math.PR) #Virology and Viral Diseases
paper · pdf · doi:10.48550/arxiv.2507.04768
openalex publication_date 2025/07/07 · openalex created_date 2025/10/20 · openalex updated_date 2026/07/28
In this article, we present two novel variants of the contact process. In the first variant individuals carry a viral load. An individual with viral load zero is classified as healthy and otherwise infected. If an individual becomes infected it begins with a viral load of one, which then evolves according to a Birth-Death process. In this model, viral load indicates severity of the infection such that individuals with a higher load can be more infectious. Moreover, the recovery times of individual is not necessarily exponentially distributed and can even be chosen to follow a power-law distribution. In the second variant individuals are permanently infected albeit in two states: actively infected or dormant. The dynamics of these individual states are again governed by a Birth-Death process. Dormant infections do not interact with neighbouring individuals but may reactivate spontaneously. Active infections reactivate dormant neighbours at a constant rate and may become dormant themselves. We present for both variants a Poisson construction. For the first model, we study the phase transition of survival and discuss existence of a non-trivial upper invariant law. Additionally, we derive a duality relationship between the two variant, which we use to uncover a phase transition regarding invariant distributions in the second variant.