TABLE 2.

Estimated number of influenza cases averted by vaccination and the associated fraction prevented, by age group — United States, 2012–13 influenza season

Age group (yrs)	Averted hospitalizations		Averted, medically attended cases		Averted cases		Fraction prevented
	No.	(95% CI)	No.	(95% CI)	No.	(95% CI)	%	(95% CI)
0–4	10,216	(5,994–16,502)	981,851	(575,222–1,591,166)	1,465,450	(859,735–2,367,044)	29.6	(28.0–30.2)
5–19	4,770	(2,869–7,722)	887,256	(529,333–1,437,481)	1,739,717	(1,046,532–2,816,363)	17.3	(16.8–17.8)
20–64	19,813	(12,887–30,107)	1,086,409	(698,241–1,666,804)	2,936,241	(1,909,887–4,461,808)	14.3	(14.0–14.5)
≥65	44,460	(17,779–82,413)	273,876	(108,797–511,422)	489,065	(195,570–906,541)	17.1	(10.5–21.3)
All ages	79,260	(39,530–136,744)	3,229,393	(1,911,592–5,206,874)	6,630,473	(4,011,725–10,551,756)	17.3	(16.2–18.0)

Abbreviation: CI = confidence interval.