{Reference Type}: Journal Article
{Title}: Noninferior Immunogenicity and Consistent Safety of Respiratory Syncytial Virus Prefusion F Protein Vaccine in Adults 50-59 Years Compared to ≥60 Years of Age.
{Author}: Ferguson M;Schwarz TF;Núñez SA;Rodríguez-García J;Mital M;Zala C;Schmitt B;Toursarkissian N;Mazarro DO;Großkopf J;Voors-Pette C;Mehta H;Hailemariam HA;de Heusch M;Salaun B;Damaso S;David MP;Descamps D;Hill J;Vandermeulen C;Hulstrøm V; ;
{Journal}: Clin Infect Dis
{Volume}: 0
{Issue}: 0
{Year}: 2024 Aug 5
{Factor}: 20.999
{DOI}: 10.1093/cid/ciae364
{Abstract}: <B>BACKGROUND: </B>The adjuvanted respiratory syncytial virus (RSV) prefusion F protein-based vaccine (RSVPreF3 OA) is approved in adults aged ≥60 years. We evaluated RSVPreF3 OA immunogenicity and safety in adults aged 50-59 years without or with increased risk for RSV disease due to specific chronic medical conditions.<BR><B>METHODS: </B>This observer-blind, phase 3, noninferiority trial included adults aged 50-59 years, stratified into 2 subcohorts: those with and those without predefined, stable, chronic medical conditions leading to an increased risk for RSV disease. Participants in both subcohorts were randomized 2:1 to receive RSVPreF3 OA or placebo. A control group of adults aged ≥60 years received RSVPreF3 OA. Primary outcomes were RSV-A and RSV-B neutralization titers (geometric mean titer ratios and sero-response rate differences) 1 month post-vaccination in 50-59-year-olds versus ≥60-year-olds. Cell-mediated immunity and safety were also assessed.<BR><B>RESULTS: </B>The exposed population included 1152 participants aged 50-59 years and 381 participants aged ≥60 years. RSVPreF3 OA was immunologically noninferior in 50-59-year-olds versus ≥60-year-olds; noninferiority criteria were met for RSV-A and RSV-B neutralization titers in those with and those without increased risk for RSV disease. Frequencies of RSVPreF3-specific polyfunctional CD4+ T cells increased substantially from pre- to 1 month post-vaccination. Most solicited adverse events had mild-to-moderate intensity and were transient. Unsolicited and serious adverse event rates were similar in all groups.<BR><B>CONCLUSIONS: </B>RSVPreF3 OA was immunologically noninferior in 50-59-year-olds compared to ≥60-year-olds, in whom efficacy was previously demonstrated. The safety profile in 50-59-year-olds was consistent with that in ≥60-year-olds.<BR><B>BACKGROUND: </B>ClinicalTrials.gov: NCT05590403.