Chapter 1: Introduction to Adjuvants

The recent pandemic has highlighted the urgency of developing vaccines that are not only swift in their deployment but also highly effective against emerging health threats. A multi-disciplinary team of researchers from institutions such as MIT and the La Jolla Institute for Immunology has been exploring a new nanoparticle adjuvant designed to bolster the immune response.

This innovative adjuvant has shown greater potency than existing options currently utilized to enhance vaccine effectiveness. In trials conducted on mice, it significantly boosted antibody production for vaccines targeting HIV, diphtheria, and influenza. The research team is optimistic about integrating this adjuvant into an HIV vaccine undergoing clinical testing.

Though the use of adjuvants to enhance vaccine efficacy has been established for decades, only a limited number have received approval from regulatory agencies. The U.S. Food and Drug Administration (FDA) has sanctioned a few, including one derived from saponin, a compound from the Chilean soapbark tree. Other approved adjuvants include aluminum hydroxide, which induces inflammation, and a specific oil-water emulsion used in flu vaccines.

Of the approved adjuvants, saponin is featured in the shingles vaccine and is also being tested in a COVID-19 vaccine. This latter vaccine employs saponins within a novel structure known as an immunostimulatory complex (ISCOM). Saponins have proven effective in promoting inflammatory immune responses and stimulating antibody production, but the exact mechanism remains to be fully understood.

“We began examining this formulation and discovered that it was remarkably effective, surpassing nearly everything we had tried.”

~ Darrell Irvine, Lead Researcher

Section 1.1: Developing the New Adjuvant

To enhance the effectiveness of this treatment, the MIT and La Jolla research team created a new adjuvant that incorporates a molecule named MPLA, aiming to replicate the success of ISCOM. When these molecules interact with toll-like receptors on immune cells, they trigger inflammation. This new formulation has been designated as SMNP (saponin/MPLA nanoparticles).

In subsequent trials, SMNP was tested in mice alongside various antigens, including two related to HIV, as well as those for diphtheria and influenza. The results indicated that these new saponin-based nanoparticles produced a significantly stronger antibody response compared to existing approved adjuvants.

Vaccines, when administered, travel through lymphatic vessels to lymph nodes, where they engage and activate B cells—the key players in antibody production. The introduction of this new adjuvant accelerates the transport of antigens to the lymph nodes before they begin to degrade. This is accomplished by stimulating unique immune cells known as mast cells.

Moreover, the adjuvant promotes the rapid death of barrier-forming macrophages, facilitating easier access for the antigens to enter the lymph nodes. Additionally, it activates inflammatory cytokines, strengthening the immune response. Researchers are optimistic that this kind of adjuvant may be beneficial for various subunit vaccines.

Chapter 2: Video Insights into Adjuvants and Vaccines

Explore the science behind the new nanoparticle adjuvant and its implications for vaccine development.

The first video provides insights into broadening B cell responses using nanoparticle adjuvants, showcasing the latest advancements in vaccine technology.

In addition, learn about the role of adjuvants in vaccines.

This second video explains what adjuvants are and their importance in vaccine efficacy, helping to demystify this crucial component of vaccine development.