Tom Hladish, PhD

Tuesday 6 July, Interactive Session 7b

Abstract: Viruses transmitted by Aedes mosquitoes such as dengue, Zika, and chikungunya have expanding ranges and appear unabated by current vector control programs. Effective control of these pathogens likely requires integrated approaches. We evaluated dengue management options in an endemic setting that combine novel vector control and vaccination using an agent-based model for Yucatan, Mexico, fit to 37 years of data. Our intervention models are informed by targeted indoor residual spraying (TIRS) experiments, trial outcomes and WHO testing guidance for the only licensed dengue vaccine, CYD-TDV, and preliminary results for in-development vaccines. We evaluated several implementation options, including varying coverage levels, staggered introductions, and a one-time, large-scale vaccination campaign. We found that CYD-TDV and TIRS interfere - while the combination outperforms either alone, performance is lower than estimated from their separate benefits. The conventional model hypothesized for in-development vaccines, however, performs synergistically with TIRS, amplifying effectiveness well beyond their independent impacts. If the preliminary performance by either of the in-development vaccines is upheld, a one-time large-scale campaign followed by routine vaccination alongside aggressive new vector control could enable short-term elimination, with nearly all cases avoided for a decade despite continuous dengue re-introductions. If elimination is impracticable due to resource limitations, less ambitious implementations of this combination still produce amplified, longer lasting effectiveness over single-approach interventions.

About: Dr. Hladish is a research scientist at the University of Florida, with affiliations in the Department of Biology and the Emerging Pathogens Institute. He received his PhD in Ecology, Evolution and Behavior from the University of Texas at Austin in 2012. He uses a range of modeling approaches to study spatiotemporal patterns of infectious disease transmission, and to design and predict the impact of intervention strategies.