ABSTRACT
Virus-like particles (VLPs) comprising viral antigenic proteins capable of inducing protective immunity are attractive candidates as alternative vaccines for a number of reasons (Roy and Noad, 2008; Kushnir et al., 2012). These include their inherent safety prole when produced by recombinant expression technology; since they contain no viral genetic material, they are incapable of accidentally transmitting infection. They can also present a means of producing practicable amounts of material, which is often difcult or impossible to obtain by culturing the target pathogen in vitro. In addition, proteins that can assemble into relatively large and regularly organized structures (VLPs) are inherently far more immunogenic than unassembled monomeric proteins (Bachmann and Jennings, 2010). These basic advantages have spurred research into VLP vaccines for more than a quarter of a century, but there are still only fully licensed VLP vaccines against two target pathogens, hepatitis B virus (HBV; Crovari et al., 1987; Krugman and Davidson, 1987) and human papillomavirus (Shank-Retzlaff et al., 2006; Monie et al., 2008), although a number of clinical trials have been conducted (Plummer and Manchester, 2010; Kushnir et al., 2012).
