• Vaccine Name: Cp15-23
• Target Pathogen: Cryptosporidium parvum
• Target Disease: Cryptosporidiosis
• Type: Subunit vaccine
• Status: Research
• Host Species for Licensed Use: Human
• Antigen: Cp15: 15 kDa sporozoite surface antigen (Liu et al., 2010); Cp23: a glycoprotein, geographically conserved among C. parvum isolates, present in both the sporozoite and merozoite stages (Liu et al., 2010)
• CP15 gene engineering:
  • Type: Recombinant protein preparation
  • Description:
  • Detailed Gene Information: Click Here.
• CP23 gene engineering:
  • Type: Recombinant protein preparation
  • Description:
  • Detailed Gene Information: Click Here.
• Immunization Route: Intramuscular injection (i.m.)
• Description: C. parvum recombinant protein vaccine that uses Cp15-23 fused protein as antigen and uses Freund’s adjuvant. (Liu et al., 2010)

Mouse Response

• Host Strain: BALB/c mice (Liu et al., 2010)
• Host age: Four-to-six-week-old (Liu et al., 2010)
• Host gender: female (Liu et al., 2010)
• Vaccination Protocol: The mice were randomly divided into different groups and were immunized subcutaneously with 10 μg of rCp15–23, rCp23, or crude extract of C. parvum in complete Freund’s adjuvant. Subsequent immunizations on days 14 and 28 were performed with 10 μg proteins in incomplete Freund’s adjuvant. The control group were given adjuvant alone. (Liu et al., 2010)
• Immune Response: Humoral: All immunized groups have specific antibody responses. The concentrations of IgG remained at low levels until days 14 after the first vaccination, whereas the second dose of vaccine rapidly and significantly boosted the responses. A peak concentration was observed after third boost. Both rCp15–23and rCp23 induced stronger antibody response than crude extract (P<0.05). (Liu et al., 2010)
  Cellular: The number of CD4+ and CD8+ T cells was increased in all immunized groups compared with the control (P<0.01), whereas the number of CD4+ T cells was much more than that of CD8+ T cells. The stimulation of cells from rCp15–23 immunized mice generated higher CD4+, CD8+ T cells and the ratio of CD4+/CD8+ than the other two immunized groups (P<0.01) (Liu et al., 2010)
  Cytokine: Significantly higher concentrations of IFN-γ or IL-12 were found in the spleen cells of all immunized groups. The IFN-γ and IL-12 levels were significantly higher in rCp15–23 immunized mice compared with the crude extract immunized mice (P<0·05). No significant difference was observed in crude extract group compared with the control group. Very low level of IL-4 was found in all the groups and no difference was found between different groups. (Liu et al., 2010)
• Challenge Protocol: 10 mice were randomly selected from each group and were challenged with 1×10^6 oocysts orally 2 weeks after the last immunization. (Liu et al., 2010)