Purified Plasmodium and vaccine composition
Inventors
Sim, B. Kim Lee • Li, Minglin • Stafford, Richard E. • Hoffman, Stephen L.
Assignees
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Publication Number
US-8992944-B2
Publication Date
2015-03-31
Expiration Date
Abstract
Disclosed are substantially purified Plasmodium sporozoites and preparations of Plasmodium sporozoites substantially separated from attendant non-sporozoite material, where the preparations of Plasmodium sporozoites have increasing levels of purity. Vaccines and pharmaceutical compositions comprising purified Plasmodium sporozoites are likewise provided. Methods of purifying preparations of Plasmodium sporozoites are also provided.
Core Innovation
The invention provides an aseptic, purified preparation of metabolically active, attenuated Plasmodium sporozoites selected from P. falciparum, P. vivax, P. malariae, P. ovale, P. knowlesi, and any combination thereof. The preparation is suitable for pharmaceutical use and is defined by a reduced amount of attendant material per 25,000 sporozoites.
The invention addresses purification of Plasmodium sporozoites by substantially purifying the sporozoites to reduce attendant non-sporozoite material. Purification concepts include aqueous pre-purification followed by sequential size-exclusion filtration using nominal or precise pore filters, including track-etched membranes, and collection and resuspension.
The invention also describes attenuation and evaluation of sporozoite potency and safety for use in vaccine and pharmaceutical compositions. Attenuation is described in connection with preventing development beyond the liver stage while maintaining potency, and potency and safety assessment is described using PfLSA-1 expression in human hepatocyte culture.
Claims Coverage
The document includes one independent claim. The claim is directed to administering an aseptic, purified preparation of metabolically active, attenuated Plasmodium sporozoites, with a quantified limit on attendant material per 25,000 sporozoites, to confer protective immunity in a human host. The inventive feature set centers on the sporozoite attributes, aseptic and pharmaceutical suitability, attendant-material reduction threshold, and the protective-immunity outcome.
Aseptic purified attenuated metabolically active Plasmodium sporozoites dose for protective immunity
Administering to a human host at least one dose of an aseptic, purified preparation of metabolically active, attenuated Plasmodium sporozoites selected from P. falciparum, P. vivax, P. malariae, P. ovale, P. knowlesi, and any combination thereof, wherein the preparation is suitable for pharmaceutical use and confers protective immunity.
Attendant material limit per 25,000 sporozoites
Providing the aseptic, purified preparation suitable for pharmaceutical use and comprising less than 85 nanograms of attendant material per 25,000 sporozoites.
Across the independent claim, protective immunity is tied to administering a dose of aseptic, purified, metabolically active, attenuated Plasmodium sporozoites suitable for pharmaceutical use, with the preparation defined by a quantitative limit of attendant material per 25,000 sporozoites.
Stated Advantages
Confers protective immunity in a human host against malaria caused by a Plasmodium-species parasite.
Reduces attendant non-sporozoite material as quantified by SGM ELISA.
Provides enhanced protection against clinical manifestations, pathology, or symptoms of malaria after later exposure versus an exposed, non-treated host.
Documented Applications
Preventive and challenge vaccine protocols supported by potency and safety assessment using PfLSA-1 expression in human hepatocyte culture and use of attenuated sporozoites to confer protective immunity.
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