Chinese clinical-stage biotech Clover Biopharmaceuticals and Nasdaq-listed biopharmaceutical company Dynavax Technologies Corporation announced on Wednesday the first participants have been dosed in Clover's global Phase 2/3 clinical trial evaluating the efficacy, safety and immunogenicity of its protein-based S-Trimer COVID-19 vaccine candidate adjuvanted with Dynavax's CpG 1018 plus alum.