Intranasal SARS-CoV-2 spike-based immunisation adjuvanted with polyethyleneimine elicits mucosal and systemic humoral responses in mice


  • L.P. Deimel
  • X. Liu
  • J. Gilbert-Jaramillo
  • S. Liu
  • W.S. James
  • Q.J. Sattentau


  • Journal of Immunological Methods


  • J Immunol Methods 511: 113380


  • The SARS-CoV-2 pandemic continues despite the presence of effective vaccines, and novel vaccine approaches may help to reduce viral spread and associated COVID-19 disease. Current vaccine administration modalities are based on systemic needle-administered immunisation which may be suboptimal for mucosal pathogens. Here we demonstrate in a mouse model that small-volume intranasal administration of purified spike (S) protein in the adjuvant polyethylenemine (PEI) elicits robust antibody responses with modest systemic neutralisation activity. Further, we test a heterologous intranasal immunisation regimen, priming with S and boosting with RBD-Fc. Our data identify small volume PEI adjuvantation as a novel platform with potential for protective mucosal vaccine development.