Table 3.
Subanalyses of vaccine efficacy (VE) against C-AOM: by age, pre-/post-booster vaccination, episode severity and by sex (intent-to-treat analysis).
| First C-AOM episodes |
All C-AOM episodesa |
|||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Number of children |
Follow-up time, person-yearsb |
Incidence, per 100,000 person-years |
Number of episodes |
Follow-up time, person-yearsc |
Incidence, per 100,000 person-years |
|||||||||
| Group |
PHiD-CV |
Control |
PHiD-CV |
Control |
PHiD-CV |
Control |
VE against first episodes, % (95% CI) |
PHiD-CV |
Control |
PHiD-CV |
Control |
PHiD-CV |
Control |
VE against all episodes, % (95% CI) |
| Total | 254 | 308 | 9018.3 | 8835.1 | 2816.5 | 3486.1 | 19.0 (4.4, 31.4) | 294 | 343 | 9475.3 | 9412.8 | 3102.8 | 3644.0 | 14.8 (−1.0, 28.2) |
| AOM by sexd | ||||||||||||||
| Females | 119 | 140 | 4370.0 | 4329.6 | 2723.1 | 3233.6 | 15.9 (−7.4; 34.1) | 139 | 150 | 4589.7 | 4590.5 | 3028.5 | 3267.6 | 7.57 (−18.40, 27.85) |
| Male | 135 | 168 | 4648.3 | 4505.5 | 2904.3 | 3728.8 | 21.7 (1.8; 37.6) | 155 | 193 | 4885.6 | 4822.3 | 3172.6 | 4002.2 | 20.54 (−0.32, 37.07) |
| Age | ||||||||||||||
| 2–11 months | 104 | 141 | 2786.8 | 2762.3 | 3731.9 | 5104.4 | 26.9 (5.9, 43.3) | 115 | 150 | 2824.7 | 2812.6 | 4071.2 | 5333.1 | 23.7 (1.3, 41.0) |
| 12–23 months | 99 | 122 | 3023.8 | 2956.5 | 3274.0 | 4126.5 | 19.7 (−4.7, 38.4) | 114 | 135 | 3176.7 | 3155.2 | 3588.6 | 4278.7 | 16.1 (−8.1, 34.8) |
| <24 months | 203 | 263 | 5810.6 | 8873.8 | 3493.6 | 2963.8 | 24.0 (8.7, 36.7) | 229 | 285 | 6001.4 | 5967.8 | 3815.8 | 4775.6 | 20.1 (3.8, 33.6) |
| 24–35 months | 47 | 42 | 2474.3 | 2390.8 | 1899.6 | 1756.7 | −10.5 (−67.5, 27.1) | 60 | 54 | 2670.3 | 2636.2 | 2246.9 | 2048.4 | −9.7 (−60.4, 25.0) |
| ≥ 36 months | 4 | 3 | 733.4 | 725.4 | 545.4 | 545.4 | −33.8 (−497.7, 70.1) | 5 | 4 | 803.6 | 808.8 | 622.2 | 494.6 | −25.3 (−366.5, 66.4) |
| Pre-/post-booster | ||||||||||||||
| Pre-booster | 124 | 177 | 3967.5 | 3925.8 | 3125.4 | 4508.6 | 30.7 (12.9, 44.9) | 140 | 191 | 4050.2 | 4039.4 | 3456.6 | 4728.4 | 27.0 (7.8, 42.2) |
| Post-booster | 132 | 123 | 5425.1 | 5373.4 | 2433.1 | 2289.1 | −6.7 (−36.4, 16.6) | 140 | 128 | 5425.1 | 5373.4 | 2580.6 | 2382.1 | −8.5 (−39.0, 15.4) |
| AOM severity: complete reporting of all symptomse | ||||||||||||||
| Mild | 119 | 120 | 9278.7 | 9202.6 | 1282.5 | 1304.0 | 1.7 (−26.7, 23.7) | 127 | 127 | 9475.3 | 9412.8 | 1340.3 | 1349.2 | 0.7 (−28.5, 23.2) |
| Moderate | 109 | 131 | 9269.9 | 9156.6 | 1175.8 | 1430.7 | 17.7 (−6.1, 36.2) | 114 | 137 | 9475.3 | 9412.8 | 1203.1 | 1455.5 | 17.3 (−6.9, 36.0) |
| Severe | 19 | 28 | 9439.5 | 9359.0 | 201.3 | 299.2 | 32.7 (−20.5, 62.4) | 19 | 28 | 9475.3 | 9412.8 | 200.5 | 297.5 | 32.6 (−20.4, 62.3) |
| AOM severity: including incomplete reporting of symptoms (≥ 1 symptom)f | ||||||||||||||
| Mild | 158 | 178 | 9198.1 | 9091.3 | 1717.8 | 1957.9 | 12.2 (−8.8, 29.1) | 175 | 191 | 9475.3 | 9412.8 | 1846.9 | 2029.2 | 9.0 (−13.2, 26.8) |
| Moderate | 126 | 146 | 9237.0 | 9135.0 | 1364.1 | 1598.3 | 14.7 (−8.3, 32.8) | 133 | 154 | 9475.3 | 9412.8 | 1403.6 | 1636.1 | 14.2 (−9.2, 32.5) |
| Severe | 22 | 28 | 9434.9 | 9359.0 | 233.2 | 299.2 | 22.1 (−36.1, 55.4) | 22 | 28 | 9475.3 | 9412.8 | 232.2 | 297.5 | 22.0 (−36.0, 55.3) |
AOM, acute otitis media; C-AOM, clinically-confirmed AOM; CI, confidence interval; post-booster, at the time of or after booster vaccination; intent-to-treat analysis, follow-up starting at the time of first vaccination. Vaccine efficacy was calculated as (1 – hazard ratio) x 100 using a Cox (first episodes) or generalized Cox (all episodes) regression model.
All C-AOM episodes, including multiple episodes in the same child.
Follow-up time for first episodes calculated as sum of follow-up periods of each child, censored at the first occurrence of a respective end point event.
Follow-up time for all episodes calculated as sum of follow-up periods of each child, from dose 1 up to end of follow-up.
Post-hoc analysis
C-AOM episodes with complete reporting of information for all 5 symptoms (∼80% of all reported C-AOM cases) on the clinical/otologic scale developed by Dagan et al.33
C-AOM episodes with information for at least 1 symptom on the clinical/otologic scale developed by Dagan et al.33; unrecorded symptoms were assumed not to be present in the patient.