Designing Public Health Policies to Mitigate the Adverse Consequences of Rural-Urban Migration via Meta-Population Modeling

This study extends the model considered in [3] (Chap. 8 in this volume) by incorporating spatially explicit migration of individuals. A three-patch meta-population model is used to explore vaccination strategies for a vaccine-preventable disease. Spatial movements of individuals between patches are mainly migration from rural to urban and peri-urban for greater economic opportunities. Stochastic simulations evaluate the effects of alternative vaccination strategies on preventing disease outbreaks, examine the distribution of possible outcomes, and compare the likelihood of outbreak mitigation and prevention across immunization policies. Two types of vaccine coverage are compared. One is homogeneous coverage, in which relevant sub-populations receive vaccination with equal probability; and the other is heterogeneous coverage, in which sub-populations can receive vaccination with different probabilities. Results suggest that when sub-populations differ in density (which may affect contact rates), heterogeneous vaccination coverage among migrants is most effective according to measures such as final epidemic size, peak size, number of vaccine doses needed to prevent outbreaks, and likelihood of containing an outbreak. This suggests that public health efforts to mitigate vaccine-preventable diseases must consider migration.