TABLE 2.

Relationship between the course of infection and antibody assays in malaria-naive, -exposed, and/or -rechallenged animals

Vaccine		Monkey no.	Prepatent period (days)	% Peak parasitemiaa	Day of cure			Course of previous infection	Course of this infection	Prechallenge sera		Secondary processing assaye
1st	2nd				Dayb	% Parasitemia	% Hematocrit			ImFc	ELISAd	1st	2nd
19	None	2581	13	0.05				Protected	Protected	>106	1/100,000	++	++
19	None	2582f	18	0.05				Protected	Protected	>106	1/200,000	+++	+++
19	None	2586	13	0.05				Protected	Protected	>106	1/500,000	++(+)	+++
19	None	2578	15	0.05				Anemic	Protected	105	1/70,000	++(+)	+++
19	None	2593	14	0.1				Virulent	Self-resolved	106	1/32,000	+/−	+/−
19	None	2572	7	0.4				Virulent	Self-resolved	105	1/16,000	+/−	+/−
None	19	2592	19	0.05				Virulent	Protected	105	1/350,000	++	++
TBVg	None	T562	9	0.8	21	0	24	Virulent	Anemic	104	1/1,000	−	−
None	None	2570	6	5.3	12	5.3	41	Virulent	Virulent	104		−	−
New	19	2573	16	0.2					Self-resolved	105	1/350,000	+/−	++
New	TBV	2575	6	10.9	12	10.9	37		Virulent	103	1/8,000	ND	ND
New	TBV	2589	7	5.5	12	5.5	41		Virulent	104	1/1000	ND	ND

^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. 

^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. 

^fMonkey 2582 died on day 20 due to heart seizure (not malaria related). 

^gTBV, TBV25H (see Materials and Methods).