TABLE 2.

Correlation between IgG responses to combinations of P. falciparum isolates tested against sera from Malawi and PNG^a

Isolate	Correlation coefficient with isolate:
	Pf2004-CSA	Pf2006-CSA	HCS3	3D7-CSA	HB3-CSA	XIE-CSA
Tested against sera from Malawi
CS2	0.698	0.702	0.576	0.551	0.197d	0.717
Pf2004-CSA		0.777	0.537	0.443	0.25b	0.899
Pf2006-CSA			0.581	0.512	0.265b	0.826
HCS3-CSA				0.741	0.409	0.537
3D7-CSA					0.418	0.404c
HB3-CSA						0.218d
Tested against sera from PNG
CS2	0.801	0.776	0.630	0.758	0.826	0.822
Pf2004-CSA		0.788	0.599	0.570	0.785	0.745
Pf2006-CSA			0.651	0.597	0.717	0.833
HCS3-CSA				0.482	0.596	0.622
3D7-CSA					0.654	0.736
HB3-CSA						0.811

^aThe values are correlation coefficients calculated by using Spearman's rho; n ranged from 57 to 63 for different comparisons for the sera from Malawi and was 54 or 55 for different comparisons for the sera from PNG. Bold type indicates isolates combinations for which corresponding graphs are shown in Fig. 3. All P values are ≤0.001 unless indicated otherwise.

^bP ≤0.05 (two-tailed).

^cP ≤0.01 (two-tailed).

^dNot statistically significantly different.