Development of safe, cost-effective vaccines is a desirable goal in practically all areas of human and animal health. In the latter field, foot-and-mouth disease (FMD) is paradigmatic of the challenge of designing strategies alternative to the conventional vaccines still used to prevent this highly transmissible, devastating livestock disease (Grubman & Baxt, 2004). Classical FMD vaccines rely on chemically inactivated FMD virus (FMDV) administered with an adjuvant and require about 7 days to induce a protective immunity that requires re-vaccination after 6-12 months to maintain its protective effect (Doel, 2005; Rodriguez & Grubman, 2009). High levels of circulating neutralizing antibodies are considered as the main correlate for FMDV protection, albeit this relationship is not absolute and differences in resistance to virus challenge can be found in animals with similar levels of neutralizing antibodies (McCullough et al., 1992). Duration of the protective immunity is essential in establishing the fitness of any FMD vaccine (Smitsaart & Bergmann, 2017), and boosting at approximately 6 monthly intervals is often required to maintain a protective response in pigs (Cox,