New mRNA vaccine aims to shield older adults from RSV

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Main Inclusion Criteria: * Sex: Male or female; female subjects may be of childbearing potential or postmenopausal. * Age: 18-45 years of age or ≥ 60 years of age at screening * Status: Healthy subjects. * Subjects must agree to not be vaccinated with any RSV vaccine while participating in this study. * Subjects must agree to not be vaccinated with any RNA-based vaccines 30 days before D1 through 30 days after D1. Main Exclusion Criteria: * Subjects with current diagnosis of RSV infection or diseases. * Previous vaccination against RSV. * Subjects with any respiratory illness deemed clinically relevant by the Investigator within the past month OR hospitalization \>24 hours for any reason within the past month prior to Day 1. * Subjects with history of myocarditis or pericarditis, or with adverse events (AEs) after mRNA vaccination that are in nature and severity beyond the common expected AEs necessitating medical intervention. * Subjects who received any non-live vaccine within 14 days prior to Day 1. * Subjects who received within 28 days prior to Day 1: (1) Any live vaccine, (2) Immunomodulators or immune-suppressive medication, (3) Granulocyte or granulocyte-macrophage colony-stimulating factor, and (4) Three or more consecutive days of systemic corticosteroids. Note: subjects on stable dose of steroid replacement (for chronic disease such as iatrogenic deficiency) of prednisone ≤10 mg/day or equivalent are allowed. * Subjects who currently receive other investigational agents or devices. * Subjects with active or suspected immunosuppression, immunodeficiency, asplenia, recurrent severe infections or autoimmune diseases. Certain immune-mediated conditions (e.g., Hashimoto thyroiditis) that are well controlled and stable are allowed. * Subjects receiving systemic antiviral therapy. * Subjects with a positive screening test for hepatitis B surface antigen (HBsAg), hepatitis C virus (HCV) antibodies, or anti-human HIV-1 and 2 antibodies, syphilis. * Subjects with a positive test for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) at Screening or on Day 1 prior to vaccine administration (JCXH-108 or placebo).