. 1999 Feb;67(2):562–567. doi: 10.1128/iai.67.2.562-567.1999

TABLE 5.

Protective efficacy of a single dose of recombinant B. anthracis against anthrax infection in guinea pigs

Vaccination^a	No. survived/no. challenged (%)^b	Time to death (days)^c	P value vs:		Serological response^f
Vaccination^a	No. survived/no. challenged (%)^b	Time to death (days)^c	PBS^d	Next entry^e	Serological response^f
ΔSterne(pPA102)	7/17 (41)	9.8 ± 1.3	0.0001	0.1534	2,111
ΔANR(pPA102)	4/17 (24)	6.0 ± 0.7	0.0001	0.3145	926
ΔSterne(pJB2)	2/19 (11)	5.1 ± 0.6	0.0001	0.0004	192
ΔSterne(pJB3)	0/19 (0)	2.8 ± 0.2	0.0002	0.6673	33
ΔANR(pJB3)	0/19 (0)	2.8 ± 0.2	0.0005	0.0005	132
PBS	0/20 (0)	2.0 ± 0.0			<10

Guinea pigs were vaccinated i.m. with a single dose of 10⁹ spores or PBS.

Animals were challenged with 2,000 LD₅₀ of Ames spores i.m. 6 weeks after vaccination.

Harmonic mean time to death ± the standard error of the mean.

P value versus the PBS control of the survival estimate calculated by using the Log Rank test from the Lifetest procedure of the SAS Statistical Software package.

P value versus the subsequent entry in this table [i.e., entry 2, ΔANR(pPA102), versus entry 3, ΔSterne(pJB2)] of the survival estimate calculated by using the Log Rank test from the Lifetest procedure of the SAS Statistical Software package.

Reciprocal geometric mean anti-PA titer of prechallenge sera (determined by enzyme-linked immunosorbent assay).