Gritstone bio, Inc. presented updated Phase 1 data from its CORAL-CEPI study, a Coalition for Epidemic Preparedness Innovations (CEPI)-funded study that is evaluating Gritstone's self-amplifying mRNA (samRNA) vaccine against COVID-19 in HIV-negative and people living with HIV (PLWH) participants. The presentation, at ESCMID Global 2024, reviewed the latest findings demonstrating the durability and potential broad utility of Gritstone's samRNA vaccine against COVID-19. The new findings came from Group D, which evaluated immunogenicity of Gritstone's sam RNA vaccine candidate delivering the Spike BA.1 variant as compared to the Spike Beta variant evaluated in Groups A-C. CORAL-CEPI (NCT05435027) is a Phase 1 study evaluating three samRNA-based SARS-CoV-2 vaccine candidates containing Spike plus other viral targets in HIV-negative (both SARS-CoV-2-naïve and convalescent) and people living with HIV (PLWH) in South Africa (N = 342).Results demonstrated: Favorable tolerability profile was consistent with previous findings, including in PLWH: All doses of the three samRNA vaccine candidates were well tolerated in both HIV-negative participants and PLWH participants irrespective of age, SARS-CoV-2 serostatus, or prior SARS-CoV-2 vaccination status at baseline; Across all vaccine candidates, IgG levels and nAb titers were high and sustained to multiple variants: All three samRNA vaccine candidates increased and maintained IgG levels and nAb titers against vaccines of concern for at least 12 months irrespective of prior SARS-CoV-2 vaccination status or serostatus; After vaccination, T cell responses were induced and/or sustained in the vast majority of subjects, including PLWH: Antigen-specific T cell responses were increased in the majority of participants tested to date after administration of any of the 3 samRNA vaccine candidates; Gritstone?s samRNA platform is well tolerated with consistent ability to drive robust and durable binding (IgG) and neutralizing antibodies (nAb) across SARS-CoV-2 variants in addition to broad T cell responses to both Spike and non-Spike epitopes.