# Immunogenicity and Protective Efficacy of Dose-Sparing Epigraph Vaccine against H3 Swine Influenza A Virus

## TL;DR

This study tests a low-dose vaccine against swine influenza and finds it can still protect against different strains, depending on the dose.

## Contribution

The study demonstrates the dose-dependent protective efficacy of the Epigraph vaccine against diverse H3 swine influenza strains.

## Key findings

- The highest dose of Epigraph vaccine protected against all three genetically divergent H3 IAV-S strains.
- Middle and lowest doses provided protection only against more or less genetically similar strains, respectively.
- Protection was measured through reduced pathology, viral load, and shedding.

## Abstract

Swine influenza A virus (IAV-S) is a highly prevalent and transmissible pathogen infecting worldwide swine populations. Our previous work has shown that the computationally derived vaccine platform, Epigraph, can induce broadly cross-reactive and durable immunity against H3 IAV-S in mice and swine. Therefore, in this study, we assess the immunogenicity and protective efficacy of the Epigraph vaccine at increasingly lower doses to determine the minimum dose required to maintain protective immunity against three genetically divergent H3 IAV-S. We assessed both antibody and T cell responses and then challenged with three H3N2 IAV-S derived from either Cluster IV(A), Cluster I, or the 2010.1 “human-like” cluster and assessed protection through reduced pathology, reduced viral load in the lungs, and reduced viral shedding from nasal swabs. Overall, we observed a dose-dependent effect where the highest dose of Epigraph protected against all three challenges, the middle dose of Epigraph protected against more genetically similar IAV-S, and the lowest dose of Epigraph only protected against genetically similar IAV-S. The results of these studies can be used to continue developing a broadly protective and low-dose vaccine against H3 IAV-S.