Virus-like particles (VLPs) have received a considerable amount of attention due to their potential application in veterinary vaccines against infectious diseases. This is the case for the rabbit haemorrhagic disease virus (RHDV), a virus which is unable to propagate in cultured cells. RHDV is the causative agent of the Rabbit Haemorrhagic Disease, one of the most economically important disease in rabbits worldwide. The RHDV capsid structure is based on a T = 3 lattice, containing 180 copies of identical VP60 subunits, similar to those of other caliciviruses. It was found that the VP1 protein of a devastating new strain, i.e. RHDVb, does not produce stable self-assembled VLPs when the capsid protein is expressed in insect cells or other systems. This application describes the generation of stable VLPs to be used as a vaccine against RHDVb. This was achieved by engineering a stable fusion protein. Collectively, this invention solves the problem of producing stable VLPs for use in vaccines against the predominant circulating strain of this virus, i.e. RHDVb.
