Moderna Already Begins Testing Brand New Covid-19 Vaccine - Mar 16, 2021 Biotechnology company Moderna announced that the first participants have been dosed in the Phase 1 study of mRNA-1283, the company’s next generation Covid-19 vaccine candidate. This Phase 1 dose-ranging study will assess the safety and immunogenicity of mRNA-1283, the company said in a statement. “We are pleased to begin this Phase 1 study of our next generation COVID-19 vaccine candidate, mRNA-1283,” said Stephane Bancel, Chief Executive Officer of Moderna. “Our investments in our mRNA platform have enabled us to develop this next generation vaccine candidate, which is a potential refrigerator-stable vaccine that could facilitate easier distribution and administration in a wider range of settings, including potentially for developing countries,” Bancel added.