Antibody response of cattle to vaccination with commercialmodified live rabies vaccines in Guatemala

Vampire bat rabies is a public and animal health concern throughout Latin America. Aspart of an ecological study of vampire bat depredation on cattle in southern Guatemala,we conducted a vaccine seroconversion study among three dairy farms. The main objec-tives of this cross sectional and cohort study were to understand factors associated withbat bites among cattle, to determine whether unvaccinated cattle had evidence of rabiesvirus exposure and evaluate whether exposure was related to bat bite prevalence, and toassess whether cattle demonstrate adequate seroconversion to two commercial vaccinesused in Guatemala. In 2012, baseline blood samples were collected immediately prior tointramuscular inoculation of cattle with one of two modified live rabies vaccines. Post vac-cination blood samples were collected 13 and 393 days later. Sera were tested for rabiesvirus neutralizing antibodies (rVNA) by the rapid fluorescent focus inhibition test (RFFIT).Across two years of study, 36% (254/702) of inspected cattle presented gross evidence ofvampire bat bites. Individual cattle with a bat bite in 2012 were more likely have a batbite in 2013. Prior to vaccination, 12% (42/350) of cattle sera demonstrated rVNA, but bitestatus in 2012 was not associated with presence of rVNA. Vaccine brand was the only fac-tor associated with adequate rVNA response of cattle by day 13. However, vaccine brandand rVNA status at day 13 were associated with an adequate rVNA titer on day 393, withanimals demonstrating an adequate titer at day 13 more likely to have an adequate titerat day 393. Our findings support stable levels of vampire bat depredation and evidence ofrVNA in unvaccinated cattle. Brand of vaccine may be an important consideration impactingadequate rVNA response and long-term maintenance of rVNA in cattle. Further, the resultsdemonstrate that initial response to vaccination is associated with rVNA status over oneyear following vaccination