• Vaccine Name: M. bovis WAg522 strain
• Target Pathogen: Mycobacterium tuberculosis
• Target Disease: Tuberculosis
• Vaccine Ontology ID: VO_0000557
• Type: Attenuated vaccine
• Antigen: The antigen for this vaccine was an attenuated strain of M. bovis called WAg522 (De et al., 1999).
• Preparation: WAg522 is the second of four M. bovis mutants selected from 440 illegitimate recombinant M. bovis mutants via their inability to grow in minimal medium (De et al., 1999).
• Virulence: This strain, along with the other tested M. bovis mutants in (De et al., 1999), was shown to be avirulent in guinea pigs following subcutaneous inoculation. Furthermore, the groups treated with WAg522 and WAg520 strains both showed significant differences in lung CFU versus nonvaccinated groups.

Guinea pig Response

• Host Strain: Duncan-Hartley
• Vaccination Protocol: Four to eight guinea pigs per group were vaccinated by subcutaneous injection with 10^5 CFU with one of the four impaired M. bovis strains or BCG. Ten animals were not vaccinated (control) (De et al., 1999).
• Side Effects: No delayed-type hypersensitivity reactions observed prior to inoculation with mycobacteria (De et al., 1999). Authors were unable to determine if nutritionally-impaired mutants influenced the development of necrotizing lesions in the lungs (De et al., 1999).
• Challenge Protocol: All animals were anesthetized eight weeks post-vaccination via intramuscular injection with 3 mg ketamine hydrochloride, followed by 10x2 CFU virulent M. bovis WAg201 introduced through mouth into the trachea via cannula. Three guinea pigs which were not challeged received 10^5 CFU of each of the four strains via subcutaneous innoculation (De et al., 1999).
• Efficacy: Significant differences in lung CFU were observed between vaccinated groups and WAg520 & WAg522 strains (De et al., 1999). WAg520 elicited 0.92, 3.83, and 2.47 log10 increases in lung, splenic, and liver tissues, respectively (see Table I, (De et al., 1999)). Macroscopic lesions were decreased in WAg520 recipients versus both non-vaccinated (significant different) and BCG-vaccinated (not significantly different) animals (see Table 2, (De et al., 1999)).