Table 3.

Antibody level and seropositivity half-life estimates (changes in antibodies from August 2007–May 2010)

	AUs		Seropositivity
Antigen	Geometric mean AU in August 2007	AU half-life (years)	Proportion seropositive in August 2007	Seropositivity half-life (years)
Strongly immunogenic*
Apical membrane antigen 1	11.43 (9.51, 13.75)	3.71 (3.00, 4.85)	0.77 (0.75, 0.80)	49.75 (17.17, 1,099.96)
Erythrocyte-binding antigen 175	3.92 (3.19, 4.81)	3.79 (3.07, 4.98)	0.63 (0.60, 0.66)	24.54 (11.49, 226.94)
Erythrocyte-binding protein-2	2.29 (1.92, 2.74)	2.76 (2.39, 3.27)	0.56 (0.53, 0.59)	8.02 (5.33, 14.70)
GLURP-R2	4.53 (3.83, 5.34)	3.13 (2.67, 3.78)	0.72 (0.69, 0.75)	18.35 (10.97, 57.97)
Liver-stage antigen-1	1.84 (1.65, 2.06)	6.30 (4.88, 8.90)	0.65 (0.61, 0.68)	16.74 (9.19, 76.57)
MSP-1 (19)	21.00 (17.28, 25.53)	2.55 (2.19, 3.06)	0.82 (0.79, 0.84)	19.06 (11.58, 48.58)
MSP-1 (42)	12.54 (10.42, 15.10)	3.49 (2.87, 4.43)	0.79 (0.76, 0.81)	44.25 (18.93, 442.43)
Moderately immunogenic†
GLURPR0	0.68 (0.59, 0.77)	3.53 (2.98, 4.35)	0.39 (0.36, 0.42)	5.33 (3.61, 9.80)
MSP-3	0.80 (0.71, 0.90)	3.25 (2.83, 3.81)	0.43 (0.40, 0.46)	5.68 (3.94, 11.07)
Thrombospondin-related adhesive protein	0.60 (0.54, 0.66)	5.55 (4.35, 7.69)	0.32 (0.29, 0.35)	8.35 (4.70, 37.32)
Poorly immunogenic‡
Circumsporozoite protein	0.56 (0.54, 0.58)	26.59 (14.39, 174.75)	0.12 (0.10, 0.15)	2.75 (1.72, 5.91)
Schizont extract	0.54 (0.52, 0.55)	47.62 (21.51, +inf)	0.07 (0.06, 0.08)	68.55 (14.66, 2,614.44)

AU = antibody level. GLURP = Glutamate rich protein; MSP = Merozoite surface protein. Estimates are shown with 95% CIs. +inf corresponds to no reduction in antibody levels.

* Seroprevalence in individuals older than 15 years, > 50% at all time points.

† Seroprevalence in individuals older than 15 years, > 30% but < 70% at all time points.

‡ Seroprevalence in individuals older than 15 years, < 30% at all time points.