TABLE 1. Efficacy of 1 dose of GSK respiratory syncytial virus RSVpreF3 vaccine against respiratory syncytial virus–associated disease among adults aged ≥60 years — multiple countries, 2021–2023.
| Efficacy evaluation period | Vaccine efficacy against outcome* | |
|---|---|---|
| RSV-associated LRTD† | RSV-associated medically attended LRTD§ | |
| Season 1¶ | 82.6 (57.9–94.1)** | 87.5 (58.9–97.6)†† |
| Season 2§§ | 56.1 (28.2–74.4)†† | —¶¶ |
| Combined seasons 1 and 2 (interim)*** | 74.5 (60.0–84.5)††† | 77.5 (57.9–89.0)†† |
Abbreviations: LRTD = lower respiratory tract disease; RSV = respiratory syncytial virus.
* Manufacturer-calculated efficacy. Includes events >14 days after injection and person-time available from the manufacturer’s pivotal phase 3 trial. Estimates adjusted for participant age and region.
† LRTD defined as two or more lower respiratory symptoms (new or increased sputum, cough, and dyspnea) or signs (new or increased wheezing, crackles or rhonchi detected during chest auscultation, respiratory rate ≥20 respirations per minute, low or decreased oxygen saturation [<95% or ≤90% if baseline was <95%], and need for oxygen supplementation) for ≥24 hours, including one or more lower respiratory signs, or three or more lower respiratory symptoms for ≥24 hours.
§ Medically attended RSV-associated LRTD defined as LRTD plus attention at one or more inpatient or outpatient health care services. Estimates were not included in per-protocol assessments.
¶ Season 1 vaccine efficacy estimates reflect efficacy against first events occurring during the first complete RSV season for Northern Hemisphere participants and a partial first RSV season for Southern Hemisphere participants (May 2021–April 2022; exact study-defined season dates were site-dependent).
** 96.95% CI; the CI for primary trial endpoint was adjusted for multiplicity.
†† 95% CI.
§§ Season 2 vaccine efficacy estimates reflect efficacy against first events occurring during the second complete Northern Hemisphere RSV season for Northern Hemisphere participants (August 2022–March 2023; exact study-defined season dates were site-dependent). In addition to Northern Hemisphere participants, Southern Hemisphere participants were also included in these analyses, but this time span reflects an interseason period with low RSV incidence in the Southern Hemisphere.
¶¶ Interim analysis underpowered to estimate efficacy.
*** Combined season 1 and 2 (interim) vaccine efficacy estimates reflect efficacy against first events occurring any time during Season 1 or Season 2. The mean time from start to end of efficacy surveillance was approximately 15 months per participant.
††† 97.5% CI; the CI for primary trial endpoint was adjusted for multiplicity.