MIT chemical engineer Daniel Anderson and colleagues from MIT, Harvard, and the University of Houston have developed a new mRNA vaccine adjuvant that significantly amplifies T-cell responses. The adjuvant consists of mRNA molecules encoding two genes that activate signaling pathways in immune cells. In mouse models of bladder cancer, colon carcinoma, melanoma, and metastatic lung cancer, lipid nanoparticles containing the adjuvant slowed tumor growth and eradicated many tumors, even without a specific cancer antigen vaccine.

When combined with antigen-specific vaccines, the response was stronger. The adjuvant also enhanced the efficacy of FDA-approved checkpoint blockade inhibitors by creating a T-cell-permissive tumor microenvironment, according to Christopher Garris, assistant professor at Harvard Medical School. Additionally, the adjuvant boosted T-cell responses to COVID and flu vaccines by 10 to 15 times.

Researchers plan further animal testing for cancer and infectious disease applications. Separately, MIT's Ana Jaklenec at the Koch Institute for Integrative Cancer Research used an adjuvant to help injectable polio vaccine induce strong mucosal immunity in the GI tract, potentially reducing viral shedding without the rare risks of the oral vaccine.