On May 25, 2021, ImmunityBio announced two South African studies to examine the potential for using its hAd5 T-cell-based COVID-19 vaccine candidate to provide extended protection for subjects with prior COVID-19 vaccinations or infections. One trial study planned the use of ImmunityBioﾒs hAd5 candidate as a ﾓUniversal Boostﾔ for healthcare workers previously vaccinated with a currently available spike-only antibody-based vaccine. The other was planned to study the safety and effectiveness of the vaccine candidate intranasally in previously infected subjects.