The results show memory T-cell recall from patients previously infected with the novel coronavirus, according to the company. ImmunityBio's novel vaccine candidate design hinges on the ability to stimulate SARS-CoV-2-specific T cells.

The vaccine candidate also features use of a second-generation hAd5, which can deliver antigens in people with preexisting adenovirus immunity, the company noted. The vaccine delivers both the spike and nucleocapsid SARS-CoV-2 proteins to stimulate memory CD4+ and CD8+ T cells, which are both important for clearing infected cells. In preclinical studies, the candidate elicited both T-cell immunity and neutralizing antibodies.

ImmunityBio aims to use the candidate to provide protection against SARS-CoV-2 infection as well as to serve as a potential therapeutic to clear infected cells in patients with COVID-19.

The vaccine candidate is currently being evaluated in a phase I clinical trial in conjunction with its affiliate, NantKWest, which is enrolling 35 healthy adults ages 18 to 55 years old in a prime, boost dose regimen. The companies are sharing equally the costs of development, manufacturing, marketing, and commercialization of the COVID-19-related products each is developing.