A Synthetic Peptide CTL Vaccine Targeting Nucleocapsid Confers Protection from SARS-CoV-2 Challenge in Rhesus Macaques

Background: Persistent transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has given rise to a COVID-19 pandemic. Several vaccines, conceived in 2020, that evoke protective spike antibody responses are being deployed mass public health vaccination programs. Recent data suggests, however, as sequence variation the genome accumulates, some vaccines may lose efficacy. Methods: Using macaque model SARS-CoV-2 infection, we tested efficacy peptide-based vaccine targeting MHC class I epitopes on nucleocapsid protein. We administered biodegradable microspheres with synthetic peptides and adjuvants rhesus macaques. Unvaccinated control vaccinated macaques were challenged 1 × 108 TCID50 units SARS-CoV-2, followed by assessment clinical symptoms viral load, chest radiographs, sampling peripheral blood bronchoalveolar lavage (BAL) fluid for downstream analysis. Results: Vaccinated animals free pneumonia-like infiltrates characteristic infection presented lower loads relative controls. Gene expression cells collected from BAL samples revealed unique signature associated enhanced development adaptive immune Conclusions: demonstrate room temperature stable peptide based known immunogenic HLA bound CTL protein can provide protection against nonhuman primates.