THEMBA II T Cell Vaccine: AAHI-SC2 (Spike), AAHI-SC3 (Nucleocapsid) saRNA COVID-19 Vaccine* May 18, 2023This is a phase 1/2 open-label study assessing the safety, reactogenicity, and immunogenicity of saRNA COVID-19 boost vaccines in participants that have been previously vaccinated against or previously infected with COVID-19.