Longitudinal deep sequencing informs vector selection and future deployment strategies for transmissible vaccines

Area of Science:

• Veterinary Virology
• Wildlife Disease Ecology
• Genomic Epidemiology

Background:

• Vaccination is crucial for disease control in humans and animals, but immunizing wildlife populations is challenging.
• Transmissible vaccines, which spread among hosts, offer a theoretical solution for vaccinating inaccessible wildlife.
• Frameworks for selecting vectors and deploying transmissible vaccines in wildlife are lacking.

Purpose of the Study:

• To investigate Desmodus rotundus betaherpesvirus (DrBHV) as a candidate vector for a transmissible rabies vaccine.
• To characterize the genetic diversity, phylogeography, and transmission dynamics of DrBHV in Peru.
• To inform the selection and deployment strategies for a DrBHV-vectored transmissible vaccine.

Main Methods:

• Deep sequencing of field-collected DrBHV samples from vampire bats (Desmodus rotundus) in Peru.
• Phylogenetic and phylogeographic analyses to understand strain distribution and evolution.
• Longitudinal resampling of marked bats to assess within-host viral kinetics and co-infections.

Main Results:

• Eleven distinct DrBHV strains were identified with varied prevalence and geographic distribution.
• DrBHV strain distribution was predictable based on host genetics and landscape topology.
• Multistrain infections (79% of cases) and evidence of latency/reactivation were observed, suggesting potential for sustained transmission.
• Pre-existing immunity and strain competition are unlikely to impede vaccine spread.

Conclusions:

• Genomic insights into DrBHV strains provide a foundation for developing a transmissible vaccine against rabies in vampire bats.
• Understanding DrBHV population genetics and transmission dynamics is critical for successful vaccine deployment.
• This study demonstrates the utility of genomics in guiding vector selection and optimizing deployment strategies for wildlife transmissible vaccines.