• Vaccine Name: C. abortus DNA vaccine encoding OmlA
• Target Pathogen: Chlamydophila abortus
• Target Disease: Abortion and fetal death
• Vaccine Ontology ID: VO_0011429
• Type: DNA vaccine
• Status: Research
• Antigen: C. abortus omlA
• omlA gene engineering:
  • Type: DNA vaccine construction
  • Description: To create the library of genetic immunization plasmids, genomic DNA of C. abortus strain B577 was physically sheared and cloned into the genetic immunization vector pCMVi-UB, which drives transcription using the strong mammalian CMV promoter (Stemke-Hale et al., 2005).
  • Detailed Gene Information: Click Here.
• DNA vaccine plasmid:
  • DNA vaccine plasmid name:
  • DNA vaccine plasmid VO ID: VO_0005027
• Immunization Route: Intramuscular injection (i.m.)

Mouse Response

• Host Strain: BALB/c
• Vaccination Protocol: Doses of 50 μg library DNA were delivered intramuscularly to the quadriceps and tibialis anterior muscles. Doses of 2.5 μg DNA were delivered to the ear skin of mice with a gene gun. C. abortus B577 was grown in BGMK cells and titrated for IFU in BGMK shell vial coverslip cultures by enumeration of chlamydial inclusions stained with FITC-labeled monoclonal antibody against chlamydial LPS. For rounds 1 and 2 of ELI, mice were boosted 9 weeks after the prime inoculation in the same manner, and for rounds 3 and 4 of ELI the mice were given an additional boost 5 weeks after the prime (Stemke-Hale et al., 2005).
• Challenge Protocol: In all cases, mice were challenged at 13 weeks with a dose of 3 × 10^6 inclusion forming units (IFU) of C. abortus administered intranasally. The positive control group representing protection received a low dose intranasal inoculation of 3 × 10^4 IFU of the same live strain four weeks prior to the high-dose challenge (Stemke-Hale et al., 2005).
• Efficacy: Genetic immunization was used to functionally test the genes of C. abortus as vaccines in a mouse challenge system. CP #7 (omlA) was significantly more protective than the genes encoding fewer than 50 amino acids (p-value of less than 0.05 when comparing lung weights). The chlamydial loads generally tracked with protection and the most protective genes were significantly lower than in unvaccinated controls (p < 0.05 in the Mann–Whitney U-test for genes CP #1, 2, 4–7, 9, 10) (Stemke-Hale et al., 2005).