Table 4. Relative incidence of combined endpoint (hospital admission or emergency room visit) following 18 month vaccination.
| Risk interval* | Endpoints during risk interval (n) | Relative Incidence(95% CI) | P value |
| Days 10 | 447 | 1.31 (1.19–1.45) | <0.0001 |
| Days 11 | 428 | 1.26 (1.14–1.39) | <0.0001 |
| Days 12 | 455 | 1.34 (1.21–1.47) | <0.0001 |
| Days 10 to 12 (Combined risk interval) | 1275 | 1.25 (1.17,1.33) | <0.0001 |
| Days 20 to 28 (Control Interval) | 3065 | NA | NA |
*Risk and control intervals expressed as days following vaccination.