Fig. 2. Immunogenicity of the YS-400 strain given via the oral route using a syringe. Six young pigs were vaccinated twice with 2 mL of the YS-400 strain and developed virus neutralization (VN) titers of 1:8-1:128 against Aujeszky's disease virus by 2 weeks after vaccination. All control pigs were negative in terms of VN titer throughout the experiment.
