Table 1.

Positive and negative predictive values of MATS for vaccine antigens, based on killing in SBA against a panel of 57 serogroup B strains by pooled sera from 13-mo-old children immunized with 4CMenB at 2, 4, 6, and 12 mo of age

	% positive predictive value*	% negative predictive value†	% accuracy‡	P value§
NHBA¶	82 (9/11)		79	0.006
NadA‖	83 (5/6)		79	0.024
fHbp**	100 (7/7)	77 (10/13)	85	0.002
Any vaccine antigen or combination of antigens	89 (39/44)		86	<0.0001

Shown is the number of strains actually killed in SBA and predicted killed by MATS for the panel of 57 strains and for subpanels in which three of four antigens were negative or at or below the PBT. Each subpanel contained 13 strains with all four antigens at or below the PBT and 7–11 strains with one antigen above the PBT. Individual MATS results for each strain are plotted in Fig. 3.

*Proportion of strains with any of the four antigens above the PBT that are killed in the SBA by immune serum.

^†Proportion of strains with all of the four antigens below the PBT that are not killed in the SBA by immune serum.

^‡Accuracy, (number of strains predicted killed by MATS and actually killed in SBA + number of strains predicted not killed by MATS and actually not killed in SBA)/total number of strains tested.

^§Fisher's exact association test for MATS predicted coverage (any of the four antigens above the PBT) vs. actual SBA killing (titer ≥8) by pooled infant sera.

^¶Twenty-four strains with fHbp, NadA, and PorA <PBT.

^‖Nineteen strains with fHbp, NHBA, and PorA <PBT.

**Twenty strains with NHBA, NadA, and PorA <PBT.