Table 3.

Immune Response to Immunization with Live Attenuated Influenza Vaccine in the LGG vs. Placebo Groups

Immunogenicity End Points	LGG N=19	PLACEBO N=20	P value
Response to A/Solomon Islands/3/2006 (H1N1)- like
Baseline
Subjects with HAI titer ≥40 - % (95% CI)	37% (16–62%)	45% (23–68%)	0.61
Geometric mean titer (95% CI)	22 (11–44)	22 (13–39)	0.94
Day 28 After vaccination
Subjects with HAI titer ≥40 - % (95% CI)	42% (20–67%)	50% (27–73%)	0.62
Geometric mean titer (95% CI)	26 (13–50)	25 (14–48)	0.98
Seroconversion
Subjects with seroconversion*- % (95% CI)	8% (0–38%)	27% (6–61%)	0.32
Response to A/Wisconsin/67/2005 (H3N2)- like
Baseline
Subjects with HAI titer ≥40 - % (95% CI)	58% (34–80%)	40% (19–64%)	0.26
Geometric mean titer (95% CI)	45 (23–88)	28 (14–59)	0.35
Day 28 After vaccination
Subjects with HAI titer ≥40 - % (95% CI)	84% (60–97%)	55% (32–77%)	0.048
Geometric mean titer (95% CI)	72 (39–131)	51 (26–100)	0.43
Seroconversion
Subjects with seroconversion*- % (95% CI)	63% (24–91%)	33% (10–65%)	0.36
Response to B/Malaysia/2506/2004 – like
Baseline
Subjects with HAI titer ≥40 - % (95% CI)	37% (16–61%)	25% (6–44%)	0.42
Geometric mean titer (95% CI)	25 (16–39)	19 (14–28)	0.36
Day 28 After vaccination
Subjects with HAI titer ≥40- % (95% CI)	53% (29–76%)	45% (23–68%)	0.63
Geometric mean titer (95% CI)	31 (24–41)	25 (17–36)	0.31
Seroconversion
Subjects with seroconversion *- % (95% CI)	42% (15–72%)	40% (16–68%)	1.00

^*Proportion of subjects with baseline titers < 1:40 who had follow-up titers of ≥ 1:40 or a fourfold increase from baseline at 14, 28 or 56 days after vaccination.