“…The concentration of the proteins was determined using Pierce BCA protein assay (Thermo Scientific, Waltham, MA, USA). The purity of the proteins was verified by Quant‐it dsDNA Broad‐Range Assay Kit (Invitrogen, Carlsbad, CA, USA; < 10 ng dsDNA/10 μg of protein), sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS‐PAGE), BacPAK RapidTiter Kit [Clontech Laboratories, Mountain View, CA, USA; 0 plaque‐forming units (pfu) live BV/ml] and limulus amebocyte lysate assay (Lonza, < 0·1 endotoxin units/100 μg of protein), as described in detail elsewhere . The VLPs and oligomeric rVP6 nanostructures used for immunizations were confirmed by negative‐staining transmission electron microscopy (TEM) using an FEI Tecnai F12 (Philips Electron Optics, Eindhoven, the Netherlands) after negative staining with 3% uranyl acetate pH 4·6 for protein morphology and integrity (Fig.…”