Study participants and clinical procedures
SECONDARY
Samples used in this exploratory analysis were obtained from a randomized, double-blind, phase 1/2a clinical trial (ClinicalTrials.gov Identifier: NCT03502707). The clinical trial was designed and overseen by the sponsor (Janssen Vaccines & Prevention B.V.) and was conducted in accordance with the Declaration of Helsinki and principles of Good Clinical Practice, and all participants provided written informed consent prior to participation. The secondary use of samples in this study was approved by the Mass General Brigham Healthcare Institutional Review Board. Participants aged ≥60 years were randomized to receive Ad26.RSV.preF, RSV preF protein, the Ad26.RSV.preF/RSV preF protein combination vaccine, or placebo. Serum samples were collected on day 1 (pre-vaccination) and on days 15, 29, and 183.Participants received Ad26.RSV.preF (1 × 10