Study participants and clinical procedures
Samples were analyzed from a subset of participants enrolled in a phase 1/2a study (ClinicalTrials.gov Identifier: NCT03502707) evaluating the safety and immunogenicity of Ad26.RSV.preF, RSV preF protein, and Ad26.RSV.preF/RSV preF protein combination vaccine regimens in adults aged ≥60 years. On day 1, participants received Ad26.RSV.preF [1 × 10