Poly(vinyl alcohol)-coated chitosan microparticles act as an effective oral vaccine delivery system for hepatitis B vaccine in rat model

The present study focused on the development of an effective oral vaccine delivery system of poly(vinyl alcohol)-coated chitosan microparticles-based recombinant hepatitis B vaccine. Chitosan microparticles were prepared by ionotropic gelation technique; they were loaded with recombinant hepatitis B vaccine and coated with poly(vinyl alcohol). The average sizes of the microparticles were measured in the range of 100-410 nm. The optimal loading capacity and loading efficiency were recorded around 3.4 and 74%, respectively. In vitro release study shows that the prepared microparticles release the antigen in a sustained manner. Moreover, the microparticles were resistant to simulated gastric environment and release the antigen in the targeted intestinal milieu. Furthermore, oral immunisation of rats with poly(vinyl alcohol)-coated chitosan hepatitis-B microparticles vaccine shows comparable seroprotective immune response to presently practiced intramuscular vaccination. The results demonstrated that poly(vinyl alcohol)-coated chitosan microparticles have the potential for being used as an oral vaccine delivery system for hepatitis B vaccine and may be a suitable alternative for needle-based vaccination.