Table 3.

Relative odds of influenza among persons who received standard dose inactivated influenza vaccine during the current season by age group, compared with young adults aged 18–49 years.

	18–49 years	50–64 years		65–74 years		≥75 years		≥65 years
	n (%)	n (%)	aOR* (95% CI †)	n (%)	aOR* (95% CI†)	n (%)	aOR* (95% CI†)	n (%)	aOR* (95% CI†)
A(H1N1)pdm09	212 (5.5)	195 (7.0)	1.4 (1.1, 1.7)	59 (4.4)	0.8 (0.6, 1.2)	18 (2.2)	0.4 (0.3, 0.7)	77 (3.5)	0.7 (0.5, 0.9)
A(H3N2)	452 (11)	318 (11)	1.1 (0.9, 1.3)	230 (15)	1.7 (1.4, 2.1)	171 (17)	2.1 (1.6, 2.6)	401 (16)	1.9 (1.6, 2.3)
Excluding 2014–15	224 (7.7)	142 (7.1)	1.0 (0.8, 1.3)	96 (10)	1.7 (1.2, 2.3)	75 (12)	2.2 (1.6, 3.2)	171 (11)	1.9 (1.4, 2.4)
Influenza B	144 (3.8)	134 (4.9)	1.4 (1.1, 1.8)	63 (4.6)	1.3 (1.0, 1.9)	18 (2.2)	0.6 (0.4, 1.1)	81 (3.7)	1.1 (0.8, 1.5)

^*aOR = Adjusted relative odds ratio. Adjusted for site, age (spline, month), month of enrollment, sex, race/ethnicity, presence of ≥1 high-risk condition, interval from symptom onset to enrollment, self-reported general health status, and season

^†CI = 95% confidence interval

Bolded text indicates statistical significance