HPV and PM specific endpoint ELISA IgG binding titers. Endpoint antibody binding titers from individual mouse sera were calculated using a cut-off of O.D. = 0.1. Graphs show geometric mean and SD. Mann-Whitney Rank sum test was used for statistical analysis using significance cut-off value of 0.05. (a) Vaccine induced anti-HPV L2 binding titers measured in sera from mice immunized with 5xL2- and 2xL2 VLPs (with and without co-display of VAR2CSA). Peptide sequences derived from the HPV L2 RG1 epitope (aa 17–31) of a range of HPV types (i.e. 16, 18, 32, 35, 45, and 51) were genetically fused to a carrier protein (accession number WP_057363222, aa 44–338) and used as capture proteins in ELISA. (b) Vaccine induced anti-HPV16, 18 and 31 L2 IgG titers, measured by HPV specific ELISA. Mice immunized with 1xL2-VLPs. For measuring HPV type specific antibody responses ELISA plates were coated with synthetic peptides derived from the HPV L2 RG1 epitope (aa 17–31) of HPV types 16, 18 or 31. (c) Vaccine induced anti-VAR2CSA IgG titers measured in sera from mice immunized with 5xL2-VLP-VAR2CSA and 2xL2-VLP-VAR2CSA. VAR2CSA was used as capture protein for the ELISA.