Australian experts have made a major discovery in vaccine science. 

Researchers have gained new insights into delta inulin as a crucial vaccine component, offering a pathway for advancing the next generation of vaccines.

Delta inulin, an adjuvant, has long been recognised for its ability to boost immune responses against a range of infectious diseases such as COVID-19, influenza, tuberculosis and hepatitis B. 

Adjuvants are substances added to vaccines to elicit stronger and longer-lasting immune responses, improving vaccine effectiveness.

Despite its established role in vaccines, the precise mechanisms underlying delta inulin’s action had remained elusive.

Now, researchers have discovered a pivotal aspect of the adjuvant’s functionality. They identified a protein known as Dendritic Cell-Specific Intercellular Adhesion Molecule-3-Grabbing Non-Integrin (DC-SIGN) as a receptor for delta inulin.

“DC-SIGN acts like a lock on cell surfaces and delta inulin functions as the key that fits into this lock, binding them together,” says Dr Erica Stewart, the lead author of the study and a researcher at the Centenary Institute’s Centre for Infection & Immunity and the University of Sydney Infectious Diseases Institute.

“This study shows that when we vaccinate with delta inulin, our cells use DC-SIGN to detect the vaccine, which then helps activate and boost the body’s immune response.”

Dr Stewart says the study’s findings carry important implications for future vaccine development.

“This study not only offers us improved understanding of the intricate mechanisms governing vaccine immune responses to delta inulin but also opens up new avenues for the development of next-generation vaccines,” Dr Stewart said.

“With this new insight into delta inulin’s mode of action, researchers can now explore the creation of new vaccines that work hand-in-hand with delta inulin, offering even greater protection against existing and emerging infectious diseases.

“This breakthrough is like finding a crucial piece of the puzzle that can make our vaccines smarter, leading to better health and safety for people worldwide,” she said.