Table 4.

Bactericidal activity of individual rabbit sera against N. meningitidis strain RH873^a

Formulation	Titerb		Pc
	Predose	Postdose 2
PBS	<4	<4
	<4	<4
GMT	<4	<4
Empty liposomes	<4	<4
	<4	<4
GMT	<4	<4
Liposomal L8 LOS*	<4	<4
	<4	16
	<4	8
	4	4
GMT	<4	8
M982 rlip-TbpB /liposomal L8 LOS (formulation 1)	<4	64
	<4	128
	<4	256
	4	256
GMT	<4	152	0.029
Mix of liposomal L8 LOS and M982 rlip-TbpB (formulation 2)	<4	32
	<4	64
	<4	128
	<4	128
GMT	<4	76	0.029
M982 rlip-TbpB	<4	4
	<4	8
	<4	8
	<4	16
GMT	<4	8	0.486

^aEach rabbit received two i.m. injections of one of the formulations at a 3-week interval. Protein and LOS doses were both 40 μg. Blood sampling was performed 2 weeks after the second injection. Bacteria were grown with chelating agent in order to express TbpB.

^bBactericidal activity is expressed as the reciprocal value of the serum dilution yielding 50% killing of bacteria. Titers corresponding to a greater than 4-fold increase over the corresponding preimmune titers are highlighted in bold.

^cFor GMT calculations and comparisons, values of <4 were considered as 2. Statistical analysis was performed using a Mann-Whitney rank-sum test. Groups were compared to the liposomal L8 LOS reference group (*) containing no rlip-TbpB.