Single-Shot Mesoporous Silica Rods Scaffold for Induction of Humoral Responses Against Small Antigens

Vaccines have shown significant promise in eliciting protective and therapeutic responses. However, most effective vaccines require several booster shots, and it is challenging to generate responses against synthetic molecules and peptides often used to increase target specificity and improve vaccine stability. As continuous antigen uptake and processing by antigen-presenting cells and persistent toll-like receptor priming can amplify humoral immunity, it is explored whether a single injection of a mesoporous silica micro-rod (MSR) vaccine containing synthetic molecules and peptides can generate potent and durable humoral immunity. A single injection of the vaccine targeting a gonadotropin-releasing hormone (GnRH) decapeptide elicits high anti-GnRH titer for over 12 months and generated higher titers than bolus or alum formulations. Targeting a Her2/neu peptide within the Trastuzumab binding domain causes immunoreactivity to Her2 on tumor cells and, MSR vaccines against nicotine generated long-term anti-nicotine antibodies. A single MSR injection induced germinal center (GC) activity for more than 3 weeks, generated memory B cells, and 7 days of immunostimulation by the vaccine is required to generate effective antibody responses. The MSR vaccine represents a promising technology to bypass the need for multiple immunizations and enhance long-term antibody production in the context of reproductive biology, cancer, and chronic addiction.