A Phase 1 Randomized, Placebo- and Comparator-controlled (Bivalent and Monovalent Components), Observer-blind Study in Older Adults to Evaluate the Safety, Reactogenicity, and Immunogenicity of 3 Dose-levels of VXB-251 (Trivalent), for the Prevention of LRTD Caused RSV, hMPV, PIV3 and to Assess Immunological Interference and Cross-reactivity.
This study is being done to find out how safe and effective a new combined vaccine candidate, called VXB-251, is for older adults. The vaccine candidate is designed to protect against three common viruses that can cause respiratory tract infections: * RSV (respiratory syncytial virus) * hMPV (human metapneumovirus) * PIV3 (parainfluenza virus type 3) Two components of this vaccine (RSV and hMPV) have already been tested in people before, as part of another study for a two-in-one vaccine. However, this is the first time that the PIV3 component and all three components together (RSV, hMPV, and PIV3) are being tested in people. The vaccine candidate will be given as a single intramuscular injection. The study will also test unlicensed comparator vaccines and a placebo (a substance that looks like the real vaccine but doesn't contain any active ingredients) that target none, one or two of these viruses to see whether combining all three components affects safety or how well the immune system responds.
• Males and females aged 60 to 83 years of age at inclusion.
• Evidence of signed and dated participant informed consent form (PICF) prior to any study procedure, indicating that the subject has been informed of all pertinent aspects of the study.
• Willingness and ability to comply with the planned study visits and calls, procedures, and restrictions for the duration of the study.
• Good health, which allows for pre-existing well controlled and low impact chronic diseases, except for the diseases listed in the exclusion criteria. A disease is defined as well controlled and has a low impact if it did not require meaningful change in therapy or unplanned medical visit(s) in the previous 3 months and allows participant's primary responsibility for self-care and daily living activities.
• Non-smoker or occasional smoker, defined as smoking less than 10 nicotine-containing cigarettes/ vapes/cigars/pipe fills per week.
• Contraception and childbearing/conception potential: only female participants with non-childbearing potential will be included. Male participants in a relationship with a female partner of childbearing potential must be willing to use a double contraceptive method together with their female partner for at least 4 weeks before and 12 weeks after the IMP injection at Visit 2 (day 1).
• Body mass index (BMI) ≥ 17.0 kg/m2 and ≤ 35.0 kg/m2.