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’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.

The multiple administration methods for the vaccine candidate offer the potential for protecting patients with a single jab followed by a nasal spray. The nasal spray and oral capsule routes also have the potential to provide mucosal immunity, which could reduce both the chance of infection and the potential spread of the virus via the respiratory tract.

The first study, which will be conducted at the Khayelitsha Clinical Research Site in South Africa, will involve 40 subjects previously infected with SARS-CoV-2 and evaluate ImmunityBio’s T-cell-based vaccine administered via multiple routes including an intranasal spray, sublingual (SL) droplet, and subcutaneous (SC) shot.

The second study, which is currently under review by SAHPRA, is designed as a Phase 1/2 trial and will evaluate the vaccine candidate as a dual SC + SL boost in subjects who have been previously vaccinated with a currently available spike-only, antibody-based vaccine. The ImmunityBio “boost” could potentially provide subjects with longer-term protection and defend against the growing number of variants.

The potential of a subcutaneous-plus-oral combination is currently under review in the U.S. (NCT04732468, NCT04591717) and the final combination of route administration to achieve maximum humoral, T cell, mucosal, and memory cell immunity will be determined upon completion of these extensive studies. Upon completion of these trials, the optimal route of administration will be determined and a pivotal, Phase 3 “universal boost” trial involving 9,670 subjects will be activated across multiple sites.