Self-amplifying mRNA Vaccine Candidates Produce Robust Antibody Titers

Gritstone bio, Inc. today presented 6-month follow-up data from its ongoing Phase 1 CORAL-CEPI and CORAL-BOOST studies, which are evaluating the company's self-amplifying mRNA (samRNA) vaccine candidates against SARS-CoV-2, at the 33rd European Congress of Clinical Microbiology & Infectious Diseases (ECCMID).

"The results shared today demonstrate that regardless of whether and/or how the immune system was previously exposed to SARS-CoV-2, our samRNA vaccine candidates are driving robust antibody titers that are sustained for at least six months in healthy adults," said Karin Jooss, EVP and Head of R&D at Gritstone bio, in a press release on April 17, 2023.

"Current vaccines against COVID-19 have demonstrated susceptibility to loss of immunity over time, posing a greater burden on individuals and our health systems."

"Developing a next-generation vaccine that drives more durable and broad neutralizing antibodies against variants of concern not included in the vaccine – both of which are demonstrated in these results - could serve as a key factor in delivering long-term, variant-proof immune protection."

"The results shared today further support our hypothesis that samRNA, unique from mRNA due to several distinct characteristics, could serve as a widely applicable next-generation vaccine platform technology against SARS-CoV-2 and beyond."

Gritstone's CORAL program applies an infectious disease approach, which aims to drive B cell and T cell immunity using samRNA against SARS-CoV-2. 

The program serves as proof of concept for applying Gritstone's platform against coronaviruses and other infectious diseases. The Bill & Melinda Gates Foundation, the U.S. NIAID, and the Coalition for Epidemic Preparedness Innovations support it.