A Randomized, Double-blind, Placebo-controlled Phase 2a Study to Evaluate the Safety and Immunogenicity of Seasonal Influenza Vaccine and Ad26.RSV.preF, With and Without Co-administration, in Adults Aged 60 Years and Older in Stable Health

The purpose of this study is to demonstrate the non-inferiority of the concomitant administration of an adenovirus serotype 26- based vaccine encoding for the respiratory syncytial virus pre-fusion F protein (Ad26.RSV.preF) and seasonal influenza vaccine versus the administration of seasonal influenza vaccine alone in terms of humoral immune response expressed by the geometric mean titers (GMTs) of hemagglutination inhibition (HI) antibody titers against all four influenza vaccine strains 28 days after the administration of influenza vaccine, and to assess the safety and tolerability of a single dose of 1\*10\^11 viral particles (vp) of Ad26.RSV.preF, administered intramuscularly to participants aged greater than or equal to 60 years separately or concomitantly with seasonal influenza vaccine.

本研究旨在验证两大核心目标：其一，在接种季节性流感疫苗28天后，以针对四种流感疫苗株的血凝抑制（hemagglutination inhibition, HI）抗体效价的几何平均滴度（geometric mean titers, GMTs）所表征的体液免疫应答维度，联合接种编码呼吸道合胞病毒（respiratory syncytial virus, RSV）预融合F蛋白的26型腺病毒载体疫苗（adenovirus serotype 26-based vaccine encoding for the respiratory syncytial virus pre-fusion F protein，缩写Ad26.RSV.preF）与季节性流感疫苗，相较于单独接种季节性流感疫苗，具备非劣效性；其二，评估肌内接种单剂1×10^11病毒颗粒（viral particles, vp）的Ad26.RSV.preF，分别单独接种或与季节性流感疫苗联合接种于60岁及以上受试者的安全性与耐受性。