Impact of age of first exposure to Plasmodium falciparum on antibody responses to malaria in children: a randomized, controlled trial in Mozambique

Table 2 Levels of antibodies at the first episode of clinical malaria (acute) and one month later (convalescence) in relation to the levels of antibodies at the immediately preceding cross-sectional visit (pre-acute) in the three study groups

Antibody	Antigen	Pre-acute	Acute			Convalescent
		GM¹	GM	Prop. diff.²	95% CI	GM	Prop. diff.	95% CI	P value³
IgG	MSP-1₁₉	0.47	0.73	1.56	1.20; 2.02	3.02	6.39	4.86; 8.40	< 0.0001
	AMA-1	0.56	0.50	0.88	0.71; 1.09	1.01	1.80	1.44; 2.25	< 0.0001
	EBA-175	0.53	0.41	0.77	0.65; 0.91	0.56	1.04	0.87; 1.24	< 0.0013
	VSA	17.46	8.60	0.49	0.27; 0.91	11.58	0.64	0.39; 1.06	< 0.0398
IgM	MSP-1₁₉	0.45	0.68	1.50	1.29; 1.73	0.67	1.47	1.26; 1.72	< 0.0001
	AMA-1	0.39	0.44	1.11	0.99; 1.26	0.48	1.23	1.08; 1.39	< 0.0083
	EBA-175	0.42	0.49	1.14	1.03; 1.26	0.51	1.18	1.06; 1.31	< 0.0046
IgG1	MSP-1₁₉	0.30	0.47	1.54	1.16; 2.04	2.32	7.48	5.54; 10.1	< 0.0001
	AMA-1	0.37	0.31	0.82	0.65; 1.04	0.64	1.73	1.35; 2.22	< 0.0001
	EBA-175	0.31	0.21	0.69	0.59; 0.81	0.27	0.87	0.74; 1.03	< 0.0001
IgG3	MSP-1₁₉	0.11	0.15	1.30	0.99; 1.70	0.49	4.36	3.28; 5.78	< 0.0001
IgG3	AMA-1	0.14	0.13	0.93	0.77; 1.12	0.29	2.04	1.66; 2.50	< 0.0001
	EBA-175	0.11	0.07	0.61	0.52; 0.72	0.09	0.80	0.67; 0.95	< 0.0001

¹Geometric means.
²The proportional difference is the ratio between the average levels of antibodies from acute (or convalescent) samples vs the levels from pre-acute samples, taking into account repeated measures for children.
³P value from Mixed-effects linear regression models using Likelihood Ratio Test.

ISSN: 1475-2875