# ASFV Proteins Presented at the Surface of T7 Phages Induce Strong Antibody Responses and Immune Cell Proliferation in Sus scrofa

## TL;DR

Researchers tested T7 phages displaying ASFV proteins as a potential vaccine in pigs, finding strong immune responses but no protection against the virus.

## Contribution

The study introduces T7 phage-displayed ASFV proteins as a novel vaccine delivery platform for African swine fever.

## Key findings

- T7 phage-displayed ASFV proteins induced high-titer antibodies and increased monocytes/CD8+ T cells in pigs.
- Despite strong immune responses, all groups developed ASF lesions, with no survival improvement observed.
- The ASFV-SC-T7 group showed higher viral loads in lungs and lymph nodes compared to controls.

## Abstract

Background/Objectives: African swine fever (ASF) causes massive global swine industry losses with no effective vaccine available. This study constructed T7 phages displaying key ASFV proteins to evaluate their potential as an ASF vaccine by assessing viral shedding and immune responses in pigs. Methods: Five ASFV proteins were displayed on T7 phages to form VLPs (ASFV-SC-T7 group), with soluble proteins (ASFV-SC group) and PBS as controls; 9 piglets were immunized, boosted at 28 days, challenged with virulent ASFV, and assessed via ELISA, flow cytometry, and real-time PCR. Results: ASFV-SC-T7 induced more high-titer antibodies and elevated monocytes/CD8+ T cells, but all groups developed ASF lesions, with ASFV-SC-T7 having higher lung/mesenteric lymph node viral loads and no survival improvement (only delayed fever). Conclusions: T7 phage-displayed ASFV proteins activate strong immunity, confirming T7 phages as a viable delivery platform, but failed to protect against virulent ASFV, requiring future optimization of antigens and regimens.