RT Journal Article SR Electronic(1) A1 Miller, Darren S. A1 Finnie, John A1 Bowden, Timothy R. A1 Scholz, Anita C. A1 Oh, Sawyin A1 Kok, Tuckweng A1 Burrell, Christopher J. A1 Trinidad, Lee A1 Boyle, David B. A1 Li, PengYR 2011 T1 Preclinical efficacy studies of influenza A haemagglutinin precursor cleavage loop peptides as a potential vaccine JF Journal of General Virology, VO 92 IS 5 SP 1152 OP 1161 DO https://doi.org/10.1099/vir.0.028985-0 PB Microbiology Society, SN 1465-2099, AB A universal influenza vaccine that does not require annual reformulation would have clear advantages over the currently approved seasonal vaccine. In this study, we combined the mucosal adjuvant alpha-galactosylceramide (αGalCer) and peptides designed across the highly conserved influenza precursor haemagglutinin (HA0) cleavage loop as a vaccine. Peptides designed across the HA0 of influenza A/H3N2 viruses, delivered to mice via the intranasal route with αGalCer as an adjuvant, provided 100 % protection following H3N2 virus challenge. Similarly, intranasal inoculation of peptides across the HA0 of influenza A/H5N1 with αGalCer completely protected mice against heterotypic challenge with H3N2 virus. Our data suggest that these peptide vaccines effectively inhibited subsequent influenza A/H3N2 virus replication. In contrast, only 20 % of mice vaccinated with αGalCer-adjuvanted peptides spanning the HA0 of H5N1 survived homologous viral challenge, possibly because the HA0 of this virus subtype is cleaved by intracellular furin-like enzymes. Results of these studies demonstrated that HA0 peptides adjuvanted with αGalCer have the potential to form the basis of a synthetic, intranasal influenza vaccine., UL https://www.microbiologyresearch.org/content/journal/jgv/10.1099/vir.0.028985-0