Figure 5.

Self-Amplifying RNA Vaccines Are Immunogenic and Protective against H1N1 in Trivalent Combination

BALB/c mice were primed i.m. with 1.5 μg each of Cal’09 H1N1, B-Mass, X31 H3N2 HA sa-RNA, 1.5 μg Cal’09 H1N1 sa-RNA alone, or 1.8 μg licensed protein flu vaccine, followed by a homologous boost 3 weeks later. H1N1 (A), H3N2 (B), or Flu B (C) specific antibody was measured by ELISA in sera 7 days after infection. (D) At 7 weeks, mice were infected i.n. with Cal’09 H1N1 influenza, and weight change was monitored daily. (E) 7 days later, the Cal’09 RNA and trivalent RNA groups from the same study were challenged with X31 H3N2 influenza, and responses were compared to new naive controls. (A)–(C) points represent individual animals and lines represent mean. (D) and (E) points represent the mean of n = 5 animals ± SEM. ***p < 0.001 between trivalent sa-RNA and naive; ###p < 0.001 between monovalent sa-RNA and naive; and xxx between monovalent and trivalent RNA (E).