TABLE 1.

Hib strains used in this study and their corresponding SBA titers obtained with quality control preparations

Hib strain designation	SBA titer (50% killing) by antibody source
	Sandoglobulin	MPR	BPIG
GB 3291a	128	1,024	16,384
DR 247	128	2,048	32,768
DR 458b	128	2,048	32,768
DR 519	512	16,384	65,536
DR 671	128	4,096	32,768
DR 715	256	4,096	32,768
DR 729	128	4,096	32,768
DR 761	128	512	16,384
DR 810	128	2,048	32,768
Eagan S-2 mutantc	No titer	No titer	No titer

^aReference Hib strain (Centers for Disease Control and Prevention) used in the generation of Hib antiserum. 

^bHib strain from the Dominican Republic used in this study for the determination of SBA titers. 

^cUnencapsulated mutant strain.