TABLE 4.

Serum bactericidal activities of sera collected at day 35

Immunization group	Serum bactericidal titera for strain:
	FA19	FA1090	MS11
TbpA − Ctb + TbpB − Ctb	800 (84 ± 5.7)	200 (64 ± 1.4)	400 (60 ± 0.7)
TbpA − Ctb	400 (83 ± 4.2)	25 (<50)b	200 (64 ± 1.4)
TbpB − Ctb	200 (64 ± 1.4)	25 (<50)b	50 (56 ± 4.9)
S.c.d TbpA + TbpB + Ctb	100 (70 ± 1.4)	25 (<50)b	25 (78)b
TbpA only	400 (71 ± 9.9)	NDc	ND

^aData are represented as the lowest reciprocal dilution that gave >50% killing. The average percent killing determined from duplicate assays ± standard deviation is shown in parentheses.

^bAssays conducted at 1/25 dilution were performed only once, and lower dilutions were not tested.

^cND, not determined.

^dS.c., subcutaueous.