A First-in-Human Study to Evaluate JCXH-105, an srRNA-based Herpes Zoster Vaccine (JCXH-105)

Inclusion Criteria: Sex: Male or female; female subjects may be of childbearing potential, of nonchildbearing potential, or postmenopausal. Age: 50 to 69 years of age, inclusive, at screening. Status: Healthy subjects. Note: Healthy status as defined by the absence of evidence of any clinically significant active or chronic disease, in the opinion of the Investigator, following a detailed medical and surgical history, a complete physical examination including vital signs, 12-lead electrocardiogram (ECG) recording, hematology, blood chemistry, serology, and urinalysis. Healthy subjects may have stable pre-existing disease defined as disease not requiring significant change in therapy or hospitalization for worsening disease during the 6 weeks prior to enrollment. Subjects must agree to not be vaccinated with any HZ vaccine while participating in this study. All values for hematology and clinical chemistry tests of blood and urine within the normal range OR showing no clinically relevant deviations based on medical history, considering stable pre-existing diseases (see Healthy Subjects above), as judged by the Investigator. Exclusion Criteria: Subjects with a history of HZ or current diagnosis of shingles. Previous vaccination against HZ. 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 the first vaccine administration (JCXH-105 or Shingrix). Subjects with history of myocarditis or pericarditis, or with AEs after mRNA vaccination that are in nature and severity beyond the common expected AEs necessitating medical intervention. Subjects who have received an mRNA-based vaccine (e.g., Spikevax, Comirnaty, etc.) 30 days prior to Day 1. Subjects who received any non-live vaccine within 14 days prior to the first vaccine administration (JCXH-105 or Shingrix). Subjects who received within 28 days prior to first vaccine administration (JCXH-105 or Shingrix): (1) Any live vaccine, (2) Immunomodulators or immune-suppressive medication, (3) Granulocyte-macrophage colony-stimulating factor, (4) Three or more consecutive days of systemic corticosteroids. Note: subjects on stable-dose steroid replacement (for chronic disease such as iatrogenic deficiency) of prednisone ≤10 mg/day or equivalent are allowed, and (5) Other investigational agents or devices. Subjects with active or suspected immunosuppression, immunodeficiency, or autoimmune disease. 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. Subjects with a positive screening test for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Subjects with a known history of active or latent tuberculosis (bacillus tuberculosis).