Mathematical models for vaccination, waning immunity and immune system boosting: a general framework

TL;DR

This paper introduces a comprehensive mathematical framework for modeling the dynamics of waning immunity and immune system boosting in infectious diseases, integrating within-host and population-level processes.

Contribution

It proposes a new SIRVS model that captures immune status changes, unifying and extending previous models of immunity waning and boosting.

Findings

Existing models are special cases of the new framework

The model can simulate various immunity waning and boosting scenarios

Provides a basis for more accurate immuno-epidemiological predictions

Abstract

When the body gets infected by a pathogen or receives a vaccine dose, the immune system develops pathogen-specific immunity. Induced immunity decays in time and years after recovery/vaccination the host might become susceptible again. Exposure to the pathogen in the environment boosts the immune system thus prolonging the duration of the protection. Such an interplay of within host and population level dynamics poses significant challenges in rigorous mathematical modeling of immuno-epidemiology. The aim of this paper is twofold. First, we provide an overview of existing models for waning of disease/vaccine-induced immunity and immune system boosting. Then a new modeling approach is proposed for SIRVS dynamics, monitoring the immune status of individuals and including both waning immunity and immune system boosting. We show that some previous models can be considered as special cases or approximations of our framework.