On Sept. 27, 2023, Gritstone bio announced that it was awarded a contract by the Biomedical Advanced Research and Development Authority (BARDA) to conduct a Phase 2b comparative study evaluating Gritstoneﾒs self-amplifying mRNA (samRNA) vaccine candidate containing Spike plus other viral targets to protect against COVID-19.

Under the contract, Gritstone bio will conduct a 10,000 participant, randomized Phase 2b double-blinded study to compare the efficacy, safety, and immunogenicity of the Gritstone next-generation COVID-19 vaccine candidate with an approved COVID-19 vaccine. The agreement is valued at up to $433 million.