TABLE 1.

The relationship between the course of infection and antibody assays in malaria-naive animals

Vaccine	Monkey no.	Parasite challenge inoculation	Prepatent period (days)	% Peak parasitemiaa	Day of cure			Course of infection	Prechallenge sera		Secondary processing assaye
					Dayb	% Parasitemia	% Hematocrit		ImFc	ELISAd	1st	2nd
P30P2MSP-119	2581	104	9	0.05				Self-resolved	105	1/500,000	+++	+
	2582	104	20	0.05				Self-resolved	105	1/450,000	+++	++
	2590	104	8	0.05				Self-resolved	106	1/500,000	+++	+++
	2593	104	8	4.3	18	4.3	30	Virulent	105	1/180,000	−	++
	2586	105	12	0.05				Self-resolved	106	1/1,000,000	+++	+++
	2571	105	4	1.2	22	1.2	21	Anemic	106	1/200,000	−	−
	2578	105	11	0.1	17		22	Anemic	105	1/250,000	+++	+++
	2572	105	5	6.0	10	6.0	48	Virulent	104	1/16,000	−	−
TBVg	2521f	104	10	0.2	11	0.2	19	Anemic	104	1/16,000	−	−
TBV	T580	104	8	5.0	12	5.0	39	Virulent	103	1/700	−	−
None	2570	104	6	6.2	11	6.2	44	Virulent			−	−
None	2584	104	5	5.3	12	5.2	55	Virulent			−	−
TBV	T562	105	6	6.9	15	6.9	30	Virulent	103	1/700	−	−
None	2592	105	4	5.9	9	5.9	44	Virulent			−	−
None	2594	105	6	5.0	9	5.0	46	Virulent			−	−

^aParasitemia of 0.05% indicates that a total of one or two parasites were seen in the 50 high-power light microscopy fields of a blood smear. 

^bCured all remaining monkeys on day 44. 

^cImF, immunofluorescence for pRBCs. 

^dELISA titration on P30P2MSP-1₁₉; titers giving an OD of 1, which is on the linear part of the titration curve. 

^eSecondary processing assay: −, no detectable processing inhibition; +/−, just-detectable inhibition; +, significant inhibition; ++, strong inhibition, +++, apparently complete inhibition. 

^fControl monkey 2521 received one vaccination of P30P2MSP-1₁₉ instead of TBV25H at the third vaccination. 

^gTBV, TBV25H.