First clinical trial of purified, irradiated malaria sporozoites in humans

Abstract

Evaluation of: Epstein JE, Tewari K, Lyke KE et al. Live attenuated malaria vaccine designed to protect through hepatic CD8 T cell immunity. Science 334(6055), 475–480 (2011).

Purified, irradiated, metabolically active sporozoites of Plasmodium falciparum (PfSPZ) have been administered to 80 volunteers through subcutaneous or intradermal routes. This PfSPZ vaccine has been shown to be safe but of low immunogenicity and hence protective efficacy as shown after challenge with infected mosquitoes. Intravenous delivery of PfSPZ in nonhuman primates induced memory CD8⁺ and CD4⁺ T cells specific for PfSPZ that reside in the liver. Further studies using PfSPZ and the intravenous route in humans are warranted to fully explore the potential of purified, attenuated sporozoites for malaria vaccine development.

Keywords::

• cellular immune response
• clinical trial
• live-attenuated sporozoites
• nonhuman primate animal model
• Plasmodium falciparum

Financial & competing interests disclosure

The author has no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

No writing assistance was utilized in the production of this manuscript.