Plasmodium falciparum: immunogenicity of alum-adsorbed clinical-grade TBV25-28, a yeast-secreted malaria transmission-blocking vaccine candidate.
Gozar, M. M. G., Muratova, O., Keister, D. B., Kensil, C. R., Price, V. L., and Kaslow, D. C. 2001. Plasmodium falciparum: Immunogenicity of alum-adsorbed clinical-grade TBV25-28, a yeast-secreted malaria transmission-blocking vaccine candidate. Experimental Parasitology 97, 61-69. The fusion of Pfs25 and Pfs28, two major surface antigens on zygotes and ookinetes of Plasmodium falciparum, as a single recombinant protein (TBV25-28) was previously shown to elicit potent transmission-blocking antibodies in mice. Clinical-grade TBV25-28 was subsequently manufactured and its potency was evaluated in rabbits. Rabbits received three doses of either clinical-grade TBV25H or clinical-grade TBV25-28 adsorbed to alum with or without QS-21. As measured in a standard membrane-feeding assay, addition of QS-21 to the formulations appeared to enhance transmission-blocking potency of rabbit sera after two vaccinations but not after three vaccinations. Surprisingly, TBV25H elicited more potent transmission-blocking antibodies than did TBV25-28, a result strikingly different from those of previous mouse experiments using research-grade TBV25-28. The apparent decrease in potency of clinical-grade TBV25-28 in rabbits appears to reflect an enhancement in potency of clinical-grade TBV25H in a new formulation rather than simply a species difference in immunogenicity of TBV25-28.
Malaria Vaccines Section, National Institutes of Health, Bethesda, Maryland 20892, U.S.A.
M M
MM
Gozar
O
O
Muratova
D B
DB
Keister
C R
CR
Kensil
V L
VL
Price
D C
DC
Kaslow
D000276:Adjuvants, Immunologic; D000534:Alum Compounds; D000818:Animals; D000913:Antibodies, Protozoan / Q000096:biosynthesis / Q000097:blood; D004797:Enzyme-Linked Immunosorbent Assay; D006863:Hydrogen-Ion Concentration; D007117:Immunization, Secondary; D017780:Malaria Vaccines / Q000276:immunology* / Q000592:standards; D016778:Malaria, Falciparum / Q000517:prevention & control*; D051379:Mice; D010963:Plasmodium falciparum / Q000276:immunology*; D015800:Protozoan Proteins / Q000276:immunology*; D011817:Rabbits; D011993:Recombinant Fusion Proteins / Q000276:immunology*; D012503:Saponins; D014614:Vaccines, Synthetic / Q000276:immunology / Q000592:standards
D000276:Adjuvants, Immunologic; D000534:Alum Compounds; D000913:Antibodies, Protozoan; D017780:Malaria Vaccines; C071284:Pfs25 protein, Plasmodium falciparum; D015800:Protozoan Proteins; D011993:Recombinant Fusion Proteins; D012503:Saponins; D014614:Vaccines, Synthetic; C041524:aluminum sulfate; C078785:saponin QA-21V1