Safety and immunogenicity of a respiratory syncytial virus prefusion F protein (RSVPreF3) candidate vaccine in older Japanese adults: A phase I, randomized, observer-blind clinical trial
Shady Kotb, Miwa Haranaka, Nicolas Folschweiller, Phoebe Nakanwagi, Céline Verheust, Nathalie De Schrevel, Marie‐Pierre David, Narcisa Mesaros, Veronica Hulstrøm
Abstract
Respiratory syncytial virus (RSV) causes lower respiratory tract infection, with a high burden of disease among adults ≥60 years. This study assessed the safety, reactogenicity, and immunogenicity of an investigational adjuvanted RSV vaccine (RSVPreF3/AS01 B ) in Japanese adults aged 60–80 years. Forty participants were randomized to receive two doses of RSVPreF3/AS01 B or the placebo, in a 1:1 ratio, two months apart, in this placebo-controlled study. Solicited administration-site and systemic adverse events (AEs) were collected within 7 days and unsolicited AEs within 30 days post-vaccination. Serious AEs (SAEs) and potential immune-mediated diseases (pIMDs) were collected throughout the study (12 months post-dose 2). RSVPreF3-specific immunoglobulin G (IgG) antibody concentrations and neutralizing antibody (nAb) titers against RSV-A were evaluated on day (D)1, D31, D61, D91 and those against RSV-B on D1, D31, D91. Solicited AEs were reported more frequently in RSVPreF3/AS01 B recipients (80.0%–90.0%) than in placebo recipients (10.0%–20.0%). Two RSVPreF3/AS01 B recipients experienced grade 3 solicited AEs. Rate of unsolicited AEs were similar (30.0%–35.0%) in both groups. No RSVPreF3/AS01 B recipient reported SAEs/pIMDs, while one placebo recipient reported two SAEs that were unrelated to vaccination. Baseline RSVPreF3-specific IgG and RSV-A/-B nAb levels were above the assay cut-off values. In the RSVPreF3/AS01 B group, RSVPreF3-specific IgG concentrations increased 12.8-fold on D31 and 9.2-fold on D91 versus baseline while nAb titers increased 7.3-fold (RSV-A) and 8.4-fold (RSV-B) on D31 and 6.3-fold (RSV-A) and 9.9-fold (RSV-B) on D91. The RSVPreF3/AS01 B vaccine was well tolerated and immunogenic in older Japanese adults. NCT04090658 .