• Vaccine Name: pVAX-15-23
• Target Pathogen: Cryptosporidium parvum
• Target Disease: Cryptosporidiosis
• Type: DNA vaccine
• Status: Research
• Host Species for Licensed Use: Human
• Antigen: Cp15: 15 kDa sporozoite surface antigen (Wang et al., 2010); Cp23(Wang et al., 2010): a glycoprotein, geographically conserved among C. parvum isolates, present in both the sporozoite and merozoite stages (Liu et al., 2010)
• CP15 gene engineering:
  • Type: DNA vaccine construction
  • Description: Amplified by PCR using a reverse primer containing a synthetic linker sequence. The amplified Cp15 was linked to Cp23 and was inserted into the pVAX1 expression vector. (Wang et al., 2010)
  • Detailed Gene Information: Click Here.
• CP23 gene engineering:
  • Type: DNA vaccine construction
  • Description: Amplified by PCR. The amplified Cp23 was linked to Cp15 and was inserted into the pVAX1 expression vector. (Wang et al., 2010)
  • Detailed Gene Information: Click Here.
• Immunization Route: Intramuscular injection (i.m.)
• Description: C. parvum DNA vaccine that express Cp15 and Cp23 in pVAX1 as antigen and express IL-12 cytokine in pMEM12R as adjuvant. (Wang et al., 2010)

Mouse Response

• Host Strain: C57BL/6 interleukin-12p40 (IL-12p40) knockout (KO) mice (Wang et al., 2010)
• Host age: six-to-eight-week-old (Wang et al., 2010)
• Host gender: female (Wang et al., 2010)
• Vaccination Protocol: Each mouse was vaccinated with with 100 μg of multivalent (pVAX-15–23) or single gene (pVAX-15 or pVAX-23) DNA vaccine alone or plus pMEM12R or in TBE on days 0, 14, and 28. Non-recombinant pVAX-1 plasmid was used as negative control. (Wang et al., 2010)
• Immune Response: Cellular: splenocytes from mice vaccinated with pVAX15–23 expressed significant INF-γ levels in response of both antigens. IFN-γ expression was significantly boosted by co-administration of pMEM12R, inducting Th1 type immune response. (Wang et al., 2010)
  Humoral: Splenocytes from vaccinated mice exhibited a strong lymphoproliferation responses 2 and 10 weeks after the final immunization, revealing sustained response of to stimulating proteins on the term of time. Stimulation of splenocytes derived from mice immunized 10 weeks before cell harvest showed significant (p < 0.01) pVAX15–23-specific proliferative response in vitro culture. pVAX15–23-DNA vaccine could induce a more sustained cellular immune response than pVAX15 and pVAX23. (Wang et al., 2010)
• Challenge Protocol: Mice were orally challenged with a single dose of 1 × 10^5 C. parvum oocysts in 200 μL of 0.15 M phosphate-buffered saline (PBS, pH 7.2) 2 weeks after the last immunization. (Wang et al., 2010)
• Efficacy: The pattern of oocysts shedding was similar in all experimental groups: shedding peak on day 10-12 post challenge and steady decline with the time course. DNA vaccination mitigated the intensity of the infection with significant decrease for mice in pVAX-15-23 group. Mice injected pVAX-15-23 and pMEM12R resolved the infection earlier than other groups. (Wang et al., 2010)