Immunogenicity and In Vivo Efficacy of Recombinant Plasmodium falciparum Merozoite Surface Protein-1 in Aotus Monkeys

Table 1 The Relation Between the Course of Infection in Vaccinated Aotus Monkeys and Neutralization of Invasion and Other Serologic Studies

	Monkeys^b			Prepatent Period^c (days)	Course^d	Invasion^e (% Infected RBCs)	IIF^f	ELISA^g
Vaccine^a	#	Sex	Species	Prepatent Period^c (days)	Course^d	Invasion^e (% Infected RBCs)	IIF^f	ELISA^g
Freund’s alone	701	Male	N	9	Virulent	1.5	<10²	<10²
	886	Female	N	12	Virulent	1.7	<10²	<10²
	184	Male	V	7	Virulent	1.3	<10²	<10²
yMSP1₁₉	331A	Male	N	11	Self-resolved	1.6	10⁴	10⁶
	218	Female	N	12	Self-resolved	1.6	10⁴	10⁵
	1193	Male	V	28	Virulent	1.7	>10⁵	10⁶
	2458	Male	V	11	Virulent	2.1	10⁴	10⁶
bGST-MSP1₄₂	202	Male	N	10	Virulent	ND	10³	10³
	E851	Male	N	11	Persistent	ND	10³	10⁴
	T212	Male	V	8	Virulent	ND	10⁴	10⁴

^ayMSP1₁₉, yeast produced fusion of the 19-kD C-terminus of MSP1₁₉; GST-MSP1₄₂, bacterial produced 42-kD C-terminus of MSP1 fused with glutathione-S-transferase.
^bSpecies of Aotus: N, A. nancymai; V, A. vociferans.
^c Prepatent period: time from inoculation of parasites to first visualized parasite in the blood.
^dVirulent, rose to above 5%, requiring treatment; self-resolved, after a low-grade parasitemia of <0.1%; Persistent, no control, but parasitemia always below 5%.
^ePercentage of red cells that contained ring-stage parasites in the invasion assay performed in the presence of Aotus sera from Day 17 after the third immunization (the day of parasite challenge).
^fIIF, indirect immunofluorescence against FCRIII that has the identical C-terminus as the FVO strain of P. falciparum.
^gELISA, enzyme-linked immunosorbent assay. End-point titers defined as the highest dilution of sera with an A₄₀₅ of 0.4 or greater (data from three different assays).

ISSN: 1528-3658