Table 1.
Incidence of RSV-Associated Respiratory Disease in the First and Second RSV Seasons (ITT Populationa)
| First RSV Season (Through 151 Days Post-dose) |
Second RSV Seasonb (362–511 Days Post-dose) |
|||
|---|---|---|---|---|
| Disease Event (n [%]) | Nirsevimab (N = 2009) |
Placebo (N = 1003) |
Nirsevimab (N = 1944) |
Placebo (N = 967) |
| Events due to RSV | ||||
| Medically attended RSV LRTIc | 24 (1.2) | 54 (5.4) | 19 (1.0) | 10 (1.0) |
| Medically attended RSV LRTI with hospitalizationc | 9 (0.4) | 20 (2.0) | 3 (0.2) | 3 (0.3) |
| Medically attended RSV LRTI (very severe)d | 7 (0.3) | 17 (1.7) | 3 (0.2) | 3 (0.3) |
| Medically attended RSV-associated LRTI on any test resulte,f | 34 (1.7) | 75 (7.5) | 35 (1.8) | 20 (2.1) |
| Hospitalization for any respiratory illness due to RSV on any test resultf,g | 15 (0.7) | 26 (2.6) | 10 (0.5) | 6 (0.6) |
| Events of any cause (inclusive of RSV) | ||||
| Medically attended LRTI of any causee | 172 (8.6) | 139 (13.9) | 134 (6.9) | 71 (7.3) |
| Hospitalization for any respiratory illness of any causeg | 45 (2.2) | 37 (3.7) | 21 (1.1) | 11 (1.1) |
Abbreviations: ITT, intent-to-treat; IV, intravenous; LRTI, lower respiratory tract infection; RSV, respiratory syncytial virus.
aITT population included all participants who underwent randomization.
bIn the second season, the number of ITT participants who were followed up for ≥362 days post-dose was used as the denominator for calculation of incidence.
cPer-protocol definition of medically attended RSV LRTI.
dRestricted to those children requiring oxygen supplementation or IV fluids for management of medically attended RSV LRTI (per protocol definition).
eMedically attended LRTI in investigators judgment, regardless of whether they met all the criteria for the per-protocol case definition of a medically attended LRTI.
fAny test result refers to either the central reference test for the trial or a local test performed in the context of clinical care.
gAny respiratory illness includes both upper respiratory tract infection and LRTI.