AS37

AS37 is an adjuvant system developed by GSK, designed to enhance the immune response to vaccines. It consists of a synthetic Toll-like receptor 7 (TLR7) agonist adsorbed to aluminum salts (alum). This formulation aims to potentiate the expansion of antigen-specific memory B-cell populations and high-avidity antibody responses, as well as induce T-cell responses. Preclinical and clinical evaluations have shown that AS37 can effectively enhance the immunogenicity of various vaccine antigens, including those for Hepatitis B, Streptococcal infections, Meningococcal C, SARS-CoV-2, Shigellosis, Staphylococcus aureus, and Pertussis. It activates immune pathways consistent with TLR7 engagement, leading to the upregulation of interferon-inducible genes, cytokines, and the activation of specific immune cells like plasmacytoid dendritic cells, intermediate monocytes, memory B cells, and T follicular helper cells. Optimal dosing has been identified to balance efficacy and safety.