CpG 1018 + alum + SCB-2019

A vaccine formulation that combines the CpG 1018 adjuvant with aluminum hydroxide (alum) and the SCB-2019 antigen. This combination has been studied in clinical trials, particularly for COVID-19 vaccination. ## Composition and Mechanism The formulation consists of three key components: 1. **CpG 1018** - A synthetic oligodeoxynucleotide that acts as a toll-like receptor 9 (TLR9) agonist adjuvant. It helps stimulate Th1-type immune responses and has been shown to induce strong CD4+ T-cell responses. 2. **Alum** (aluminum hydroxide) - A traditional vaccine adjuvant that enhances immune response. 3. **SCB-2019** - A recombinant protein antigen. The combination of CpG 1018 with alum creates a dual-adjuvant system designed to enhance immune response to the SCB-2019 antigen. CpG 1018 is known for its ability to elicit Th1-type immune responses, produce IL-12, IL-18, and IFN-γ from macrophages and natural killer cells, and its involvement in antibody production and B cell proliferation. ## Development Status This vaccine formulation has undergone clinical testing, with a global Phase II/III trial demonstrating safety and immunogenicity in adolescents aged 12 to 17 years. The CpG 1018 adjuvant itself has been extensively tested in clinical trials and is FDA-approved for use in vaccines, including the hepatitis B vaccine HEPLISAV-B.