Evaluation of antibody response in horses after vaccination with an inactivated Getah virus vaccine using an accelerated immunization schedule

ABSTRACT Antibody response in horses after accelerated-schedule Getah virus vaccination was evaluated for its potential adoption during outbreaks. One-year-old Thoroughbred horses received two doses of priming vaccinations following an accelerated schedule (accelerated group: 14-day interval, n = 30) or the conventional schedule (control group: 28-day interval, n = 30). At Day 14, both groups showed similar seropositive rates (66.7% in control group and 73.3% in accelerated group) and geometric mean (GM) virus-neutralizing titers (5.2 [95% confidence interval (CI), 3.0-8.8] in control group and 5.3 [95%CI, 3.1-8.9]). At Day 28, the controls showed a lower seropositive rate (40.0%) and GM titer (2.2 [95%CI, 1.5-3.3]), whereas these figures were significantly higher in the accelerated group, at 80.0% and 7.0 (95%CI, 4.2-11.6, P