Protection of guinea pigs and swine by a recombinant adenovirus expressing O serotype of foot-and-mouth disease virus whole capsid and 3C protease

Two recombinant adenoviruses were constructed expressing foot-and-mouth disease virus (FMDV) capsid and 3C/3CD proteins in replicative deficient human adenovirus type 5 vector. Guinea pigs vaccinated with 1–3 × 108 TCID50 Ad-P12 × 3C recombinant adenovirus were completely protected against 10,000 GID50 homologous virulent FMDV challenge 25 days post vaccination (dpv). Ad-P12 × 3CD vaccinated guinea pigs were only partially protected. Swine were vaccinated once with 1 × 109 TCID50 Ad-P12 × 3C hybrid virus and challenged 28 days later. Three of four vaccinated swine were completely protected against 200 pig 50% infectious doses (ID50) of homologous FMDV challenge, and vaccinated pigs developed specific cellular and humoral immune responses. The immune effect of Ad-P12 × 3C in swine further indicated that the recombinant adenovirus was highly efficient in transferring the foreign gene. This approach may thus be a very hopeful tool for developing FMD live virus vector vaccine.