Title
Logistical constraints lead to an intermediate optimum in outbreak response vaccination.
Abstract
Dynamic models in disease ecology have historically evaluated vaccination strategies under the assumption that they are implemented homogeneously in space and time. However, this approach fails to formally account for operational and logistical constraints inherent in the distribution of vaccination to the population at risk. Thus, feedback between the dynamic processes of vaccine distribution and transmission might be overlooked. Here, we present a spatially explicit, stochastic Susceptible-Infected-Recovered-Vaccinated model that highlights the density-dependence and spatial constraints of various diffusive strategies of vaccination during an outbreak. The model integrates an agent-based process of disease spread with a partial differential process of vaccination deployment. We characterize the vaccination response in terms of a diffusion rate that describes the distribution of vaccination to the population at risk from a central location. This generates an explicit trade-off between slow diffusion, which concentrates effort near the central location, and fast diffusion, which spreads a fixed vaccination effort thinly over a large area. We use stochastic simulation to identify the optimum vaccination diffusion rate as a function of population density, interaction scale, transmissibility, and vaccine intensity. Our results show that, conditional on a timely response, the optimal strategy for minimizing outbreak size is to distribute vaccination resource at an intermediate rate: fast enough to outpace the epidemic, but slow enough to achieve local herd immunity. If the response is delayed, however, the optimal strategy for minimizing outbreak size changes to a rapidly diffusive distribution of vaccination effort. The latter may also result in significantly larger outbreaks, thus suggesting a benefit of allocating resources to timely outbreak detection and response
Year
DOI
Venue
2018
10.1371/journal.pcbi.1006161
PLOS COMPUTATIONAL BIOLOGY
Field
DocType
Volume
Stochastic simulation,Transmission (mechanics),Population,Mathematical optimization,Herd immunity,Biology,Vaccination,Outbreak,Dynamic models,Bioinformatics,Transmissibility (vibration)
Journal
14
Issue
Citations 
PageRank 
5
0
0.34
References 
Authors
1
3
Name
Order
Citations
PageRank
Yun Tao100.34
Katriona Shea211.06
Matthew J. Ferrari312.08