Table 3.
Vaccine Efficacy of a Single Dose of RSVPreF3 OA Against a First Occurrence of RSV-LRTD and RSV-ARI After Different Follow-up Times Postvaccination (Modified Exposed Population)
| Follow-up Postvaccination | RSV-LRTD, % (CIa) | Severe RSV-LRTD,b % (CIa) | RSV-ARI, % (CIa) | |||
|---|---|---|---|---|---|---|
| With Season as a Covariate | Without Season as a Covariate | With Season as a Covariate | Without Season as a Covariate | With Season as a Covariate | Without Season as a Covariate | |
| Season 1 (6.7 mo) | NA | 82.6 (57.9, 94.1) | NA | 94.1 (62.4, 99.9) | NA | 71.7 (56.2, 82.3) |
| 1 y (12 mo) | NA | 78.9 (57.6, 90.5) | NA | ND | NA | ND |
| Season 1 + mid-season 2 (13.9 mo) | 77.3 (60.2, 87.9) | 80.9 (66.7, 89.8) | 84.6 (56.4, 96.1) | 86.8 (63.0, 96.6) | 56.5 (41.6, 68.0) | 62.8 (50.3, 72.6) |
| Season 1 + 2 (17.8 mo) | 67.2 (48.2, 80.0) | 74.5 (60.0, 84.5) | 78.8 (52.6, 92.0) | 82.7 (61.6, 93.4) | 52.7 (40.0, 63.0) | 62.1 (52.1, 70.3) |
“Season 1” follow-up included cases collected from day 15 post–dose 1 until 11 April 2022 (end of Northern Hemisphere season 1). The “1 year” follow-up included cases collected from day 15 post–dose 1 until dose 2 administration or until 30 September 2022 (end of Southern Hemisphere season 1) if no dose 2 was administered. “Season 1 + mid-season 2” follow-up included cases collected from day 15 post–dose 1 until dose 2 administration or until 30 September 2022 (end of Southern Hemisphere season 1) if no dose 2 was administered and cases collected from dose 2 until 30 November 2022 (mid–Northern Hemisphere season 2). “Season 1 + 2” follow-up included cases collected from day 15 post–dose 1 until dose 2 administration or until 30 September 2022 (end of Southern Hemisphere season 1) if no dose 2 was administered and cases collected from dose 2 until 31 March 2023 (end of Northern Hemisphere season 2). Vaccine efficacy was estimated using a Poisson model adjusted for age, region, and season (“with season as a covariate”) or for age and region (“without season as a covariate”; post hoc analyses).
Abbreviations: CI, confidence interval; NA, not applicable; ND, not determined; RSV, respiratory syncytial virus; RSV-ARI, RSV-related acute respiratory illness; RSV-LRTD, RSV-related lower respiratory tract disease confirmed by the adjudication committee; RSVPreF3 OA, RSV prefusion F protein–based vaccine.
a96.95% CI for primary endpoint (RSV-LRTD, season 1); 97.5% CI for confirmatory secondary endpoint (RSV-LRTD, season 1 + 2); 95% CI for other endpoints.
bSevere disease according to either of the 2 case definitions (definition 1 based on clinical signs/investigator assessment or definition 2 based on supportive therapy, see Supplementary Methods).