• Vaccine Name: P. falciparum Pfen Protein Subunit Vaccine
• Target Pathogen: Plasmodium spp.
• Target Disease: Malaria
• Vaccine Ontology ID: VO_0011418
• Type: Subunit vaccine
• Status: Research
• Pfen gene engineering:
  • Type: Recombinant protein preparation
  • Description:
  • Detailed Gene Information: Click Here.
• Adjuvant:
  • Adjuvant name:
  • VO adjuvant ID: VO_0000133
• Immunization Route: Intraperitoneal injection (i.p.)

Mouse Response

• Host Strain: Swiss
• Vaccination Protocol: Mice were injected intraperitoneally with r-Pfen emulsified in Freund's adjuvant at 21-day intervals (the first injection was 100 μg of r-Pfen in complete Freund's adjuvant, followed by 50 μg for the two boosters in incomplete Freund's adjuvant). In one control group, mice were injected in parallel with a recombinant Drosophila odorant binding protein OSF (as an irrelevant His-tagged protein control) emulsified in complete Freund's adjuvant. The other control group received no injections. After three immunizations, the antibody titers against r-Pfen were monitored (Pal-Bhowmick et al., 2007).
• Challenge Protocol: Mice having anti-r-Pfen antibody titers greater than 1:300,000 were then challenged with the lethal strain of P. yoelii (strain 17XL; 10^6 parasites per mouse), and parasitemia was monitored daily (Pal-Bhowmick et al., 2007).
• Efficacy: All the control mice and the mice immunized with the irrelevant His-tagged protein developed a high degree of parasitemia (>17% on average) by day 4 postchallenge, whereas r-Pfen-immunized mice showed <1% parasitemia at that time point. The highest average parasitemia values were 70% and 40% for nonimmunized mice and mice injected with irrelevant His-tagged protein, respectively. However, among the mice immunized with r-Pfen, there was significant delay in the increase in parasitemia, and the highest average parasitemia was about 20% on day 8 postchallenge. The averages of these groups were compared using one-way analysis of variance, which showed that the mice immunized with enolase were significantly protected (Pal-Bhowmick et al., 2007).