On Feb. 11, 2021, ImmunityBio and NantKwest announced they had received FDA authorization to expand Phase I testing of a bivalent hAd5 T-cell COVID-19 vaccine. The FDA authorized the expansion of a currently active multi-cohort trial of the subcutaneous version of the vaccine in order to study the addition of sublingual boosts.

The FDA also authorized a second Phase I study that examined the addition of an oral boost to the subcutaneous prime administration.