BACKGROUND: Whole parasite vaccines provide a unique opportunity for dissecting 
immune mechanisms and identify antigens that are targeted by immune responses 
which have the potential to mediate sterile protection against malaria 
infections. The radiation attenuated sporozoite (PfSPZ) vaccine has been 
considered the gold standard for malaria vaccines because of its unparalleled 
efficacy. The immunogenicity of this and other vaccines continues to be 
evaluated by using recombinant proteins or peptides of known sporozoite 
antigens. This approach, however, has significant limitations by relying solely 
on a limited number of known pathogen-associated immune epitopes. Using the full 
range of antigens expressed by the sporozoite will enable the comprehensive 
immune-profiling of humoral immune responses induced by whole parasite vaccines. 
To address this challenge, a novel ELISA based on sporozoites was developed.
RESULTS: The SPZ-ELISA method described in this report can be performed with 
either freshly dissected sporozoites or with cryopreserved sporozoite lysates. 
The use of a fixative for reproducible coating is not required. The SPZ-ELISA 
was first validated using monoclonal antibodies specific for CSP and TRAP and 
then used for the characterization of immune sera from radiation attenuated 
sporozoite vaccinees.
CONCLUSION: Applying this simple and highly reproducible approach to assess 
immune responses induced by malaria vaccines, both recombinant and whole 
parasite vaccines, (1) will help in the evaluation of immune responses induced 
by antigenically complex malaria vaccines such as the irradiated SPZ-vaccine, 
(2) will facilitate and accelerate the identification of immune correlates of 
protection, and (3) can also be a valuable assessment tool for antigen discovery 
as well as down-selection of vaccine formulations and, thereby, guide vaccine 
design.