Even when vaccines are rapidly developed and shown to be efficacious and safe, vaccination campaigns continue to be hampered by public hesitancy and by challenges distributing vaccines equitably around the globe. Vaccine hesitancy, where individuals refuse or delay vaccination, has been a persistent challenge, affecting a third to a quarter of individuals in the US and globally. Inequitably, it affects racial and ethnic minority communities particularly strongly, and in 2019 the World Health Organization named vaccine hesitancy as one of the top-ten threats to global health. Needle-based injections, which increase vaccine reactogenicity, are a significant driver of vaccine hesitancy. A second fundamental hurdle in equitable availability of vaccines involves the chain of distribution. Most vaccines must be transported and stored within a continuous cold-chain to prevent loss of potency, making global distribution challenging. In the face of these limitations, lineage-directed or other multi-dose strategies involving the sequential delivery of antigens across weeks or months are receiving increasing scientific interest towards a range of diseases currently lacking vaccines, yet the issues of global distribution and patient acceptance are exponentially more challenging with repeated dosing. This project seeks to utilize supramolecular peptide biomaterial vaccines engineered specifically for the sublingual route to provide for effective vaccination. The project aims to design a shelf- stable, easily administered, and minimally reactogenic vaccine platform as an alternative to needle-based vaccines relying on continuous refrigeration. We will build upon the innovative self-assembling peptide platforms recently introduced by our group and others in order to elucidate factors necessary for maximizing and adjusting sublingual vaccination responses. In preliminary work, we have established the proof-of- concept of a tablet-based supramolecular vaccination technology, Supramolecular Immunization with Peptides SubLingually (SIMPL), but the key design parameters for adjusting the strength and quality of immune responses remain to be articulated. Therefore the objective of the project is to articulate these design rules, using multifactorial Design-of-Experiments (DOE) approaches to ascertain how supramolecular size, charge, mucoadhesivity, and adjuvant complexation influences the lymphatic trafficking and humoral and cellular responses sublingually in mouse models. Critical proofs-of-concept will be established for influenza, zika, and HIV-1. Finally, SIMPL will be established as a basis for multi-dose lineage-directed vaccination in mice and rabbits. Our collaborative team is facilitated by the proximity of the Pratt School of Engineering and the Duke Human Vaccine Institute (DHVI), providing a unique opportunity to combine perspectives from Bioengineers and biomaterials specialists (Collier lab) and immunologists and vaccine specialists (Fouda lab).

Global access to vaccines, especially those that require multiple doses, is challenged by patient hesitancy and logistical hurdles that hinder equitable distribution. This project seeks to develop a new vaccine platform for sublingual vaccination based on the self-assembly of protein fragments. Shelf-stable, easily administered, and minimally reactogenic, the platform aims to provide an alternative to needle-based vaccines relying on continuous refrigeration.