Variation in host home range size decreases rabies vaccination effectiveness by increasing the spatial spread of rabies virus

1. Animal movement influences the spatial spread of directly-transmitted
wildlife disease through host-host contact structure. Wildlife disease
hosts vary in home range-associated foraging and social behaviors, which
may increase the spread and intensity of disease outbreaks. The
consequences of variation in host home range movement and space use on
wildlife disease dynamics are poorly understood, but could help to predict
disease spread and determine more effective disease management strategies.
2. We developed a spatially-explicit individual-based model to examine the
effect of spatiotemporal variation in host home range size on the spatial
spread rate, persistence, and incidence of rabies virus (RABV) in raccoons
(Procyon lotor). We tested the hypothesis that variation in home range
size increases RABV spread and decreases vaccination effectiveness in host
populations following pathogen invasion into a vaccination zone. 3. We
simulated raccoon demography and RABV dynamics across a range of
magnitudes and variances in weekly home range size for raccoons. We
examined how variable home range size influenced the relative
effectiveness of three components of oral rabies vaccination (ORV)
programs targeting raccoons—timing and frequency of bait delivery, width
of the ORV zone, and proportion of hosts immunized. 4. Variability in
weekly home range size increased RABV spread rates by 1.2 - 5.2-fold
compared to simulations that assumed a fixed home range size. More
variable host home range sizes decreased relative vaccination
effectiveness by 71% compared to less variable host home range sizes under
conventional vaccination conditions. We found that vaccination timing was
more influential for vaccination effectiveness than vaccination frequency
or vaccination zone width. 5. Our results suggest that variation in
wildlife home range movement behavior increases the spatial spread and
incidence of RABV. Our vaccination results underscore the importance of
prioritizing individual-level space use and movement data collection to
understand wildlife disease dynamics and plan their effective control and
elimination.