Table 2.

Comparison of Geometric Mean Titers (GMTs) From Hemagglutination Inhibition Assays at Days 0, 30, and 180 for Recipients of Standard-Dose and High-Dose Influenza Vaccines, by Influenza Season and Vaccine Strain

Season, Strain	Day 0, GMT (95% CI)			Day 30, GMT (95% CI)			Day 180,a GMT (95% CI)
	Standard Dose	High Dose	P valueb	Standard Dose	High Dose	P valueb	Standard Dose	High Dose	P valueb
2011–2012	n = 33	n = 31		n = 33	n = 31		n = 24	n = 26
A/California/07/2009(H1N1)	16.6 (10.3–26.7)	17.1 (11.3–25.9)	.917	27.4 (17–44.3)	78.2 (45.1–135.7)	.005	28.3 (15.3–52.4)	59.7 (33.5–106.3)	.074
A/Victoria/210/2009(H3N2)	7.3 (5.3–10.0)	8.9 (6.5–12.3)	.360	10.2 (7.0–14.8)	26.2 (17.1–40.0)	.001	9.4 (6–14.8)	22.3 (14.5–34.3)	.006
B/Brisbane/60/2008	11.6 (8.6–15.5)	15.3 (10.3–22.6)	.248	14.3 (11.1–18.4)	25.6 (18.7–34.9)	.004	15.4 (11.8–20.2)	22.9 (16.3–32)	.069
2012–2013	n = 65	n = 58		n = 65	n = 58		n = 59	n = 53
A/California/07/2009(H1N1)	32.3 (23.8–43.9)	23.6 (16.7–33.4)	.178	50.0 (37.4–67)	45.6 (32.9–63.2)	.672	51.8 (37.8–71.1)	46.8 (33.2–65.9)	.663
A/Victoria/361/2011(H3N2)	6.2 (5.4–7.1)	7.2 (6.1–8.3)	.152	14.2 (11.0–18.4)	23.4 (17.6–31)	.011	13.4 (10.3–17.5)	24.7 (18.3–33.2)	.003
B/Texas/6/2011	9.1 (7.5–11)	7.9 (6.5–9.5)	.285	17.4 (13.9–21.9)	26.0 (21.2–31.9)	.010	18.9 (14.9–23.9)	25.3 (20.8–30.9)	.063

Abbreviation: CI, confidence interval.

^a Six participants in the standard-dose group and 5 in the high-dose group died before collection of blood samples at day 180.

^b By the t test.