Table 4.

Vaccine efficacy (VE) against B-AOM by age and pre-/post-booster vaccination (intent-to-treat cohort).

	First B-AOM episodes							All B-AOM episodesa
	Number of children with ≥ 1 episode		Follow-up time, person-years		Incidence, per 100,000 person-years			Number of episodes		Follow-up time, person-years		Incidence, per 100,000 person-years
Group	PHiD-CV	Control	PHiD-CV	Control	PHiD-CV	Control	VE against first episodes, % (95% CI)	PHiD-CV	Con-trol	PHiD-CV	Control	PHiD-CV	Control	VE against all episodes, % (95% CI)
Total	45	67	9396.9	9271.0	478.9	722.7	33.6 (3.2, 54.5)	47	70	9475.3	9412.8	496.0	743.7	33.3 (2.26, 54.5)
Age
2–11 months	20	35	2817.7	2798.3	709.8	1250.8	43.3 (1.7, 67.3)	21	35	2824.7	2812.6	743.4	1244.4	40.3 (−4.0, 65.7)
12–23 months	12	26	3150.1	3105.2	380.9	837.3	54.2 (9.3, 76.9)	13	27	3176.7	3155.2	409.2	855.7	52.1 (6.7, 75.5)
<24 months	32	61	5967.8	5903.5	536.2	1033.3	48.0 (20.3, 66.1)	34	62	6001.4	5967.8	566.5	1038.9	45.4 (15.8, 64.6)
24–35 months	13	6	2637.5	2578.6	492.9	232.7	−114.0 (−463.0, 18.7)	13	7	2670.3	2636.2	486.8	265.5	−83.3 (−359.1, 26.8)
≥ 36 months	0	0	791518.0	788879.0	0.0	0.0	U	0	1	803565.0	808797.0	0.0	0.1	100 (−3774.3, 100)
Pre-/post-booster
Pre-booster	24	47	4033.0	4007.9	595.1	1172.7	49.3 (17.1, 69.0)	26	48	4050.2	4039.4	641.9	1188.3	46.0 (10.9, 67.3)
Post-booster	19	20	5363.8	5263.2	354.2	380.0	6.0 (−76.2, 49.8)	19	20	5425.1	5373.4	350.2	372.2	5.8 (−76.0, 49.6)

AOM, acute otitis media; B-AOM, bacteriologically-confirmed AOM; CI, confidence interval; post-booster, at the time of or after booster vaccination; U, undefined; intent-to-treat analysis, follow-up starting at the time of first vaccination; per-protocol analysis, follow-up starting 2 weeks post-dose 3. Vaccine efficacy was calculated as (1 – hazard ratio) x 100 using a Cox (first episodes) or generalized Cox (all episodes) regression model.

^aAll B-AOM episodes, including recurrent episodes in the same child.