TABLE 2.

Anti-FHA and anti-PT IgG titers in sera of i.n. immunized mice^a

Immunization	Anti-FHA IgG titer	Anti-PT IgG titer
B. pertussis
BPSM	1.6 × 104	NDb
BPSA87	<10	ND
BPSA90	<10	ND
Antigens
FHA	3.6 × 105	<10
Fha44	3.1 × 104	<10
PT	<10	4.1 × 105
FHA + PT	1.7 × 106	7.3 × 105
Fha44 + PT	2.5 × 105	6.5 × 105
PBS	<10	<10

^aFor B. pertussis-infected mice, serum samples were collected and pooled from eight mice per group 8 weeks after infection. For mice immunized with purified antigens, serum samples were collected and pooled from 10 mice per group 2 weeks after the last immunization.

^bND, not determined.