Matuschewski, "The Plasmodium
sporozoite journey: A rite of passage," Trends in Parasitology, vol.
In this study, measurements of oocysts, sporocysts, and
sporozoites of the Caryospora species observed were obtained.
When the single dose was increased to 120 mg/kg administered two weeks prior to
sporozoite challenge, a low positive luminescence with 97.9% of suppression was observed at 24 hours in the liver stage period; afterward the photon signal was observed to be negative at 48 and 72 hours in all animals.
Phylogenetic Gene ID classification Trophozoite Schizont Merozoite PF3D7_0204700 Clade 2 + + + PF3D7_0919500 Clade 4 nd nd nd Blood stage Gene ID Gametocyte I Gametocyte II Gametocyte III PF3D7_0204700 + + nd PF3D7_0919500 nd nd nd Mosquito/sexual stage Gene ID Gametocyte IV Gametocyte V Ookinete
Sporozoite PF3D7_0204700 nd + nd + PF3D7_0919500 nd nd nd + Phylogenetic classification (see Figure 1); +: protein expression is detected; nd: not detected.
Innovations in
sporozoite cryopreservation by Sanaria, Inc (Rockville, MD) (24) initiated an effort to overcome these limitations by vialing aseptic, cryopreserved
sporozoites into an FDA-regulated product called PfSPZ Challenge, colloquially referred to as "challenge in a bottle." This mosquito-free challenge delivers
sporozoites by needle inoculation and is capable of reasonable infectivity rates at a dose of 3,500
sporozoites per vial.
The earliest report which revealed its significance in malaria demonstrated that exogenous administration of unpurified mouse serum IFN was able to protect CF-1 mice from PbA
sporozoite infection [206].
It is clear that daily spraying with pyrethrum had the most beneficial effect with a 91% reduction in the spleen rate, despite a 2.86%
sporozoite rate.
The new vaccine, known as PfSPZ, employs an old but more radical approach using whole Plasmodium falciparum
sporozoites (SPZs), a mobile immature form of the parasite.
After the bite occurs, infectious malaria parasites in the immature,
sporozoite stage of their life cycle first travel to the liver, where they multiply, and then spread through the bloodstream, at which time symptoms develop.