Safety and Immunogenicity Trial of PepGNP-COVID19 Vaccine in Adults

This Phase 1 clinical trial will evaluate the safety, reactogenicity, and immunogenicity of PepGNP-COVID19, a synthetic nanoparticle-based, T cell-priming peptide vaccine against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), when administered as a booster dose in healthy adults. PepGNP-COVID19 is designed to induce broad and durable T cell-mediated immune responses by delivering conserved SARS-CoV-2 peptides covalently bound to carbohydrate-coated gold nanoparticles. The goal is to enhance tissue-resident cytotoxic T lymphocytes in the respiratory tract and reduce the need for frequent antigen updates. This is a randomized, participant-blinded, dose-ranging, multi-site trial in healthy adults 18-64 years of age, with a target of 8 of 20 participants in each cohort being \> / = 50 years of age. A total of 60 participants will be enrolled, with 20 participants assigned to each cohort. Participants will receive a single intradermal injection (ID) of PepGNP-COVID19 at one of three dose levels: 0.83 nmol, 2.5 nmol, or 7.5 nmol in a volume of 0.05 mL. The primary objective is to evaluate the safety, reactogenicity, and tolerability of a single intradermal dose of PepGNP-COVID19 at three dosage levels in previously vaccinated healthy adults, as assessed by: a) Solicited local and systemic adverse events (AEs) through 7 days after vaccination; b) Unsolicited AEs through 28 days after vaccination; c) Abnormal clinical safety laboratory AEs through 14 days after vaccination; d) Serious adverse events (SAEs), medically attended adverse events (MAAEs), new-onset chronic medical conditions (NOCMCs), adverse events of special interest (AESIs), and potentially immune-mediated diseases (pIMDs) through 6 months after vaccination; e) Vaccine tolerability assessment on Day 29. The secondary objectives are to assess systemic T cell-mediated immune responses and to evaluate systemic anti-Spike humoral immune responses following a single ID of PepGNP-COVID19.