This is a phase 1/2 study looking to enroll a total of 262 patients.~For phase 1, two cohorts will be explored (18-64 age group and 65+ age group) for a total of 72 subjects. The subjects will be enrolled and randomized to either placebo or JCXH-221. A low dose of JCXH-221 will be explored vs placebo for each age group first. A high dose for those 2 cohorts will be explored once all safety data is reviewed.~Once all of Phase 1 data has been reviewed, Phase 2 enrollment will open. In this portion of the trial, subjects will be enrolled and randomized to either JCXH-221 or a FDA approved Active comparator (Pfizer, Moderna, etc.). A total of 190 patients will be enrolled.
The goal of this clinical trial is to learn about, test, and compare JCXH-221 in healthy volunteers. The main aims to answer are:~To assess the safety and tolerability of the JCXH-221 vaccine in healthy adult subjects~To identify an optimal dose for the JCXH-221 vaccine in healthy adult subjects~To assess the humoral immunogenicity of the JCXH-221 vaccine in healthy adult subjects~To characterize the cellular immunogenicity of the JCXH-221 vaccine in healthy adult subjects~Participants for Phase I will be randomized to either JCXH-221 or placebo. In Phase 2, participants will be randomized to either JCXH-221 or a FDA approved Active comparator.